The problem:
I am in process of implementing a scheduler for my advisor in school. The scheduler supposes to setup a 15 minutes interval time slot from 8:00 AM to 5:00 PM, Monday to Friday. In addition, the advisor will have to specify the start and end dates of the scheduler. The scheduler will also feature an option to specify if the 15 minutes time slot is not open. Meaning my advisor will be able to mark specific time slot as NOT AVAILABLE.
What I have so far:
I have created a simple class:
public class TimeSlot
{
public DateTime dateTime
{
get;
set;
}
public bool isAvailable
{
get;
set;
}
TimeSlot(DateTime dt, bool Avalible)
{
dateTime = dt;
isAvailable = Avalible;
}
}
The class basically represents an object for one time slot in the scheduler. I also have a list of time slots that keeps a list of the valid time slots:
List<TimeSlot> TSList = new List<TimeSlot>();
Note that a valid time slot means the following:
Date is within: Monday to Friday.
Time is within: 8:00 AM to 5:00 PM
Time slots are within: 15 minutes interval.
In addition, I have a method that fill in the TSList as the following:
private void button_Next_Click(object sender, RoutedEventArgs e)
{
/* Getting the values of fromDate and toDate from the GUI controls*/
DateTime fromDate = datePicker1.SelectedDate.Value;
DateTime toDate = datePicker2.SelectedDate.Value;
while (fromDate <= toDate)
{
/*This ensures that we only deal with days Monday to Friday*/
if (fromDate.DayOfWeek.ToString() != "Saturday" && fromDate.DayOfWeek.ToString() != "Sunday")
{
/*PROBLEM HERE!!*/
}
/*Updating fromDate: Incrementing fromDate by 1 day*/
fromDate = fromDate.AddDays(1);
}
}
Notes that I was only able to satisfy the first condition in my valid time slot conditions. Thus, I was only able to restrict the dates to be within Monday to Friday range.
The questions:
I am trying to achieve the missing two valid conditions for a time slot:
How to restrict the times to be only 8:00am to 5:00 pm?
How to make time slots separated by 15 minutes interval?
First, please use DayOfWeek.Saturday and DayOfWeek.Sunday for the comparision, converting to a string is not necessary...
Then just use a simple loop like
DateTime startSlot = fromDate.Date.AddHours(8); // Starts at 8:00AM
while (startSlot.Hour < 17) {
// Construct time slot class
startSlot = startSlot.AddMinutes(15);
}
This gives you startSlot values starting at 8:00am at every date ranging to 5pm (i.e. the last one is 4:45pm).
Why are you considering building this out of nothing?
Why are you not starting with one of the many calendar management programs that are available off the shelf? For example, Microsoft Outlook contains calendar and schedule management, and you can do all of what you describe, easily. It also integrates with other scheduling tools via .ICS files, it syncs with mobile devices, syncs with Google Calendar, and so on.
But there are lots of other options. Google Calendar is another obvious one.
I don't know why you would ever consider starting from scratch. Unless it's an academic exercise (and no, I don't mean that you work in academia), then you should use larger building blocks to start.
It's like building a structure, starting with sand and water, instead of pre-fabricated concrete block.
Just quick implementation. Let me know if you need some comments.
// Round interval
const int roundInterval = 15;
var remainder = fromDate.TimeOfDay.Minutes % roundInterval;
var curTime = remainder == 0 ? fromDate : fromDate.AddMinutes(roundInterval - remainder);
curTime = curTime.AddSeconds(-curTime.TimeOfDay.Seconds);
var delta = TimeSpan.FromMinutes(roundInterval);
while (curTime < toDate)
{
while (curTime.DayOfWeek == DayOfWeek.Saturday || curTime.DayOfWeek == DayOfWeek.Sunday)
{
curTime = curTime.Date.AddDays(1);
}
if (curTime.TimeOfDay.Hours < 8)
{
curTime = curTime.AddHours(8 - curTime.TimeOfDay.Hours);
curTime = curTime.AddMinutes(-curTime.TimeOfDay.Minutes);
continue;
}
if (curTime.TimeOfDay.Hours >= 17)
{
curTime = curTime.AddHours(24 - curTime.TimeOfDay.Hours);
curTime = curTime.AddMinutes(-curTime.TimeOfDay.Minutes);
continue;
}
TSList.Add(new TimeSlot(curTime, true));
curTime = curTime.Add(delta);
}
}
DateTime myScheduledTimeSlot = new DateTime(2010, 10, 26, 8, 45, 0);
// Use existing check to check day of week constraint...
// Check if the datetime falls on a correct minute boundary
switch (myScheduledTimeSlot.Minute)
{
case 0:
case 15:
case 30:
case 45:
// The time slot is valid
break;
default:
// The time slot is not valid
break;
}
It is pretty simple to check whether it falls in a 15 minute slot as you don't have weird boundaries keeping every hour identical. I'd recommend checking out Quart.NET if you want to save some time doing eventing/scheduling.
Related
I'm working on an asp.net core MVC project. This project about identifying online and offline users, I have two datetime, one of the stores in a database, and another is current datetime, and I must know that time stored in a database elapsed from 61 seconds or not?
I subtract two Datetime and finally use TotalSeconds property.but my output is -22095 or 2319208 and so on.
public void CheckUserStatus()
{
DateTime now = DateTime.Now;
var userTime = _context.Sessions.Where(x => x.LastOnline).Select(x => new {x.LastConnectTime, x.Id});
foreach (var time in userTime)
{
TimeSpan diffrence = now.Subtract(time.LastConnectTime);
int mytime = Convert.ToInt32(diffrence.TotalSeconds);
if ( mytime < 61)
{
Console.WriteLine(time.Id);
}
}
}
I expect out of time base on seconds, for example, right now my output is -22095 or 2319208, and so on but I don't know 2319208 is a regular time or not?
You can easily check that like this :
DateTime now = DateTime.Now;
TimeSpan past = now - now.Subtract(TimeSpan.FromSeconds(60));
TimeSpan post = now - now.Subtract(TimeSpan.FromSeconds(61));
Console.WriteLine(now);
// Should be False: Passed time is less than 60 seconds
Console.WriteLine(past.TotalSeconds > 60);
// Should be True: Passed time is more than 60 seconds
Console.WriteLine(post.TotalSeconds > 60);
Using System.Windows.Form.Timer the interval is an int, which gives a maximum interval limit of around 25 days. I know I could create some arbitrary algorithm to start another timer once the limit is reached, but that's just daft.
MISLEADING-IGNORE-->So if I want to set it to around 29 days (2619609112.7228003) milliseconds?<--MISLEADING-IGNORE
EDIT:
The real question here is how can I set System.Windows.Form.Timer to a value higher than maxInt?
The purpose is that I need to set an interval from whenever to the first day of the next month, so it could be 28,29,30 or 31 days, and when that interval expires, calculate the interval to the next first day of the month.
(Basically a Crystal Report is to be run on the 1st day of the month and printed (around 500 pages), because of the length of the reports it is to be run out of hours so it doesn't tie up the printer.)
e.g. run it today (today is 1/12/15), 1/1/16 is next 'first day of the month' so set the interval to the milliseconds between now and then.
1/1/16 comes around so the timer ticks, then calculate and set the interval for 1/2/2016 (the next first day of the month).
#SeeSharp - I did see that question, but I am working on a legacy app and am unsure of the implications of changing the timer, but if I can't get this timer to work I may look at the threading one, thanks.
EDIT2: Thanks for all of your suggestions, I've opted for a 3rd party plugin called FluentScheduler
Set the timer interval to one day (say) and use it to count the number of days up to 29.
Edit
Set the timer to half a day (say) and use it to check that the date is the first of the month.
How about a Month timer - This will fire close to midnight when the month changes. May be that suits your requirement better ?
If we have to consider day-light saving too, then perhaps the timer should fire at 2:00 AM on the 1st day of month so I'll make it configurable.
Here is a code to explain my idea -
public class MonthTimer : IDisposable
{
public event EventHandler<MonthChangedEventArgs> MonthChanged;
DateTime mLastTimerDate;
Timer mTimer;
public MonthTimer(TimeSpan timeOfFirstDay)
: this(DateTime.Now, timeOfFirstDay)
{
}
public MonthTimer(DateTime currentDate, TimeSpan timeOfFirstDay)
{
mLastTimerDate = currentDate.Date;
var milliSecondsInDay = new TimeSpan(1, 0, 0, 0).TotalMilliseconds;
Contract.Assert(timeOfFirstDay.TotalMilliseconds <= milliSecondsInDay); // time within 1st day of month
DateTime currentDateLastSecond = currentDate.Date.AddDays(1).AddTicks(-1); // one tick before midnight
TimeSpan timeSpanInCurrentDate = currentDateLastSecond.Subtract(currentDate); // remaining time till today ends
// I want the timer to check every day at specifed time (as in timeOfFirstDay) if the month has changed
// therefore at first I would like timer's timeout to be until the same time, following day
var milliSecondsTillTomorrow = (timeSpanInCurrentDate + timeOfFirstDay).TotalMilliseconds;
// since out milliseconds will never exceed - . Its okay to convert them to int32
mTimer = new Timer(TimerTick, null, Convert.ToInt32(milliSecondsTillTomorrow), Convert.ToInt32(milliSecondsInDay));
}
private void TimerTick(object state)
{
if(DateTime.Now.Month != mLastTimerDate.Month)
{
if (MonthChanged != null)
MonthChanged(this, new MonthChangedEventArgs(mLastTimerDate, DateTime.Now.Date));
}
mLastTimerDate = DateTime.Now.Date;
}
public void Dispose()
{
mTimer.Dispose();
}
}
public class MonthChangedEventArgs : EventArgs
{
public MonthChangedEventArgs(DateTime previousMonth, DateTime currentMonth)
{
CurrentMonth = currentMonth;
PreviousMonth = previousMonth;
}
public DateTime CurrentMonth
{
get;
private set;
}
public DateTime PreviousMonth
{
get;
private set;
}
}
client code
// Check the new month around 2 AM on 1st day
mMonthTimer = new MonthTimer(new TimeSpan(2, 0, 0));
mMonthTimer.MonthChanged += mMonthTimer_MonthChanged;
One thing I'm not using System.Threading.Timer, therefor the even handler will be called on a separate thread & not UI thread as incase of System.Windows.Forms.Timer if this is an issue in yr case do let me know.
Also do write me a comment if it serves yr purpose or any if any issues
Try Microsoft's Reactive Framework (NuGet "Rx-Main").
You can write this:
Observable
.Timer(DateTimeOffset.Now.AddDays(29.0))
.Subscribe(x =>
{
/* 29 Days Later */
});
I have a little calendar tool in C# and I am trying to figure out how to do a conversion from one array of DateTime objects to another. Here are the details:
I start off with collection of DateTime object
IEnumerable<DateTime> slots = GetSlots();
where each DateTime represents that starting time of an available slot (think open slot in calendar) All slots are for 30 minutes This is a given. So for example:
var slots = new List<DateTime>()
slots.Add(DateTime.Today + new TimeSpan(5,00, 0));
slots.Add(DateTime.Today + new TimeSpan(9,00, 0));
slots.Add(DateTime.Today + new TimeSpan(9,30, 0));
slots.Add(DateTime.Today + new TimeSpan(10,00, 0));
slots.Add(DateTime.Today + new TimeSpan(10,30, 0));
slots.Add(DateTime.Today + new TimeSpan(11,00, 0));
slots.Add(DateTime.Today + new TimeSpan(16,30, 0));
in the above example, it means i am free:
From 5:00 - 5:30
From 9:00 - 9:30
From 9:30 - 10:00
From 10:00 - 10:30
From 10:30 - 11:00
From 11:00 - 11:30
From 4:30 - 5:00
because i take the time from the item in the collection as the start time and simply add 30 minutes to it and that is considered a free slot.
I now have the requirement to take a larger time window (lets use 2 hours) and find out how many 2 hour slots free i have so I now need to take this array of dates and "merge" into into bigger buckets. Given the bigger bucket is 2 hours (120 minutes), I want a function like this
IEnumerable<DateTime> aggregateArray = MergeIntoLargerSlots(slots, 120);
I would basically have to loop through the slots array above and "merge" items that are lined up next to each out to make bigger buckets. If any of the merged items is 2 hours long then that should show up as an entry in the resulting array. Using the example above the resulting aggregateArray would have 2 items in the collection it that would have the times:
9AM (because i have a free slot from 9-11 AM (120 mins).
9:30AM (because i have a free slot from 9:30-11:30 AM (120 mins).
NOTE: 30 minutes "chunks" are the smallest interval so DON'T need to include 9:05 to 11:05 as an example
So given the previous array I have two 2 hour windows of time free in the day
I am struggling to figure out how this MergeIntoLargerSlots function would work so i would hoping to get some suggestion for how to approach this problem.
This only works for half hour intervals, you can figure out to make it work for others if you need to.
public List<DateTime> MergeIntoLargerSlots(List<DateTime> slots, int minutes)
{
int count = minutes/30;
List<DateTime> retVal = new List<DateTime>();
foreach (DateTime slot in slots)
{
DateTime end = slot.AddMinutes(minutes);
if (slots.Where(x => x >= slot && x < end).Count() == count)
{
retVal.Add(slot);
}
}
return retVal;
}
Here's a brief explanation of my problem solving approach; I take in the minutes and the slots list. I add minutes to get an end time which gives me range. From there, I use the Where operator to produce and IEnumerable<DateTime> from slots that has the slots in that range. I compare the result to the count variable I got from doing minutes/slotLength if the numbers match then you have the necessary slots. With your sample data the result of the Where for 9 AM would have 4 values in it; 9, 9:30, 10 and 10:30, ofc the count is 4, 120/30 == 4, so that gets added to retVal. The same would be true for 9:30, no other times would be returned.
Evan beat me to and did it with one less loop, but here was my solution:
private List<DateTime> MergeArray(List<DateTime> slots, int minutes)
{
var segments = minutes / InitialSegment;
var validSegments = new List<DateTime>();
foreach (var slot in slots.OrderBy(x => x))
{
var validSegment = true;
for (var i = 0; i < segments-1; i++)
{
var next = slot.AddMinutes(InitialSegment * (i + 1));
if (slots.All(x => x != next))
{
validSegment = false;
break;
}
}
if (validSegment)
validSegments.Add(slot);
}
return validSegments;
}
Assuming that your original list is sorted (if it is not, make it so it is), you could loop through your original list and check whether adjacent items are consecutive (i.e. whether the start times have a distance of exactly 30 minutes). Always keep track of the first item in the current series of consecutive timeslots - once you reach four of them (with 4 consecutive 30 minutes timeslots adding up to a possible two-hour timeslot; other timeslot sizes obviously require different factors), save a new two-hour timeslot into your resulting list and update your reference to the beginning of the current series of consecutive items.
Untested, so please consider this as pseudocode:
var twoHourSlots = new List<DateTime>();
int consecutiveSlotsCount = 0;
DateTime? previousSlot;
foreach (DateTime smallSlotStart in slots) {
if (previousSlot.HasValue) {
if (smallSlotStart - previousSlot.Value == new TimeSpan(0, 30, 0)) {
consecutiveSlotsCount++;
} else {
consecutiveSlotsCount = 0;
}
}
if (consecutiveSlotsCount == 4) {
twoHourSlots.Add(smallSlotStart - new TimeSpan(1, 30, 0));
consecutiveSlots = 0;
previousSlot = null;
} else {
previousSlot = smallSlotStart;
}
}
Some things to note:
I am using arithmetic operators on DateTime values. Check the docs to find out more; they do handy things and often let you work with TimeSpan values automatically.
I am using a TimeSpan constructor that takes hours, minutes and seconds several times. So that's what the three numbers mean.
I have declared previousSlot, a variable that keeps track of the last slot looked at (to compare to the current one), as DateTime? (again, check the docs if you are not sure what a nullable type is). That is because in the first iteration of the foreach loop, there is no previous slot to look at and the loop has to behave differently.
Likewise, previousSlot is set to null when we have found a 2-hour slot, as the last 30-minute slot of the found 2-hour slot should not be counted to the next possible 2-hour slot.
Once four consecutive 30-minute slots have been found, one hour and thirty minutes are subtracted from the beginning of the last one. That is because the thirty minutes after the beginning of the last 30-minute slot will be part of the resulting 2-hour slot.
I would create a TimeInterval class since there are a lot of other interesting things you can do with it.
public sealed class TimeInterval
{
public DateTime Start { get; private set; }
public DateTime End { get { return Start.AddMinutes(Duration); } }
public double Duration { get; private set; }
public TimeInterval(DateTime start, int duration)
{
Start = start;
Duration = duration;
}
public IEnumerable<TimeInterval> Merge(TimeInterval that)
{
if(that.Start >= this.Start && that.Start <= this.End)
{
if(that.End > this.End)
Duration += (that.Duration - (this.End - that.Start).TotalMinutes);
yield return this;
}
else
{
yield return this;
yield return that;
}
}
}
And this is an O(n) merge algorithm that will work for intervals of arbitrary sizes (in minutes).
//the `spans` parameter must be presorted
public IEnumerable<TimeInterval> Merge(IEnumerable<TimeInterval> spans, int duration)
{
var stack = new Stack<TimeInterval>();
stack.Push(spans.First());
foreach (var span in spans.Skip(1))
foreach(var interval in stack.Pop().Merge(span)) //this enumeration is guaranteed to have either one element or two elements.
stack.Push(interval);
return from interval in stack where interval.Duration >= duration select interval;
}
In my project I can block internet access completely in specific times but in a current date.
I did this by using a timer. This timer checks the start time and end time and also controls in every 5 seconds to disable and enable internet connection by using the start time and end time given by user. Now I want to do the same thing in different days not only for the current date. I want to check every day in every 5 seconds of a day by timer if a disable/enable time interval is given by the user for that specific date.
if (currentDate == chosenDate)
{
if ((currenttime >= starttime) && (currenttime <= endtime))
{
timerForHour.Enabled = true;
if (isConnectedToNetwork)
{
findNetworkName();
Disable(networkName);
}
}
else
{
exitFlag = true;
Enable(networkName);
}
}
else if(currentDate!=chosenDate)
{
}
This is my code what am I going to do in this else if section?. Thanks.
I think you are going about this the wrong way. Don't think about it in terms of "if it's today or not", instead think about it in a more general way: "does the day match or not, if it does then are we within the time range acceptable?". Without knowing more about how you are storing the day / time ranges you are using I can offer the following using LINQ:
IsInternetAllowed = false;
DateTime dateOfInterest = datesToRestrict
.FirstOrDefault(dt => dt.Date == DateTime.Now.Date);
if (dateOfInterest != null)
{
if (timesToAllowDict.ContainsKey(DateTime.Now.Date))
{
List<Tuple<DateTime, DateTime>> lstAllowed =
timesToAllowDict[DateTime.Now.Date];
IsInternetAllowed = lstAllowed
.FirstOrDefault(time =>
DateTime.Now.Time > time.Value1 &&
DateTime.Now.Time < time.Value2) != null;
}
}
if (IsInternetAllowed)
Enable(networkName);
else
Disable(networkName);
I make the following assumptions about your data:
There are potentially multiple times allowed per day.
Any time that network access is not allowed it is disabled.
You store your allowed dates & times in a
Dictionary<DateTime, List<Tuple<DateTime, DateTime>>> structure.
That structure represents Date, List of times allowed (start then end).
Each day is added separately (one dictionary key per day allowed).
It is likely that with some streamlining you could remove the need to have a dictionary structure and only use the start & end times instead.
i need to calculate the number of workdays between two dates. a workday is any day between Monday through Friday except for holidays. the code below does this, but it uses a loop. does anyone see a way to get rid of the loop or at least optimize it?
thanks
konstantin
using System;
using System.Linq;
namespace consapp
{
static class Program
{
static void Main(string[] args)
{
var holidays = new DateTime[] { new DateTime(2010, 11, 23), new DateTime(2010, 11, 30) };
var date_start = new DateTime(2010, 12, 3);
var date_end = date_start.AddDays(-9.9);
var duration = (date_end - date_start).Duration();
for (var d = date_end; d < date_start; d = d.Date.AddDays(1))
{
if (holidays.Contains(d.Date) || d.DayOfWeek == DayOfWeek.Saturday || d.DayOfWeek == DayOfWeek.Sunday)
{
duration -= TimeSpan.FromDays(1) - d.TimeOfDay;
}
}
Console.WriteLine(duration);
}
}
}
I would investigate an algorithm like the following. (Sorry no code provided.)
Count the number of full 7-day weeks between your start and end date. You should be able to do this with .NET DateTime and TimeSpan objects.
For each full 7-day week, add 5 days to your result.
Figure out the partial weeks including your start and end dates.
Loop through your holidays and reduce your result by 1 for each holiday between your start and end date. Looping is better here because there are likely far fewer holidays to loop over than days between your start and end date.
Have fun!
EDIT: For source code, check out this answer: Calculate the number of business days between two dates?
Is performance really problematic here? Unless profiling suggests otherwise I'd guess this code doesn't really slow down your application. It's performance should be fine unless you calculate the workdays for thousands of long intervals per second.
If your holiday list is much larger than just two dates then convert it into a HashSet<T> which has O(1) lookup time.
And of course you can turn around the code. So you don't loop over the days in the interval, but over the holidays. Then you just calculate the number of week-days in the interval(should be simple math) and subtract the number of holidays that fall on a week-day.
If it's really necessary you can pre-calculate the workdays since some fixed date, and then subtract the lookup result from the beginning of the period from the lookup result from the end of the period.
if you want faster code, don't loop over each day in the range:
remove from your list of holidays all holidays that fall on sunday or saturday, then use the timespan methods to give you the number of days between the two dates. With a little math (think about integer division by 7) you can get the number of mon-thursday days in that range, subtract the number of holidays that don't fall on the weekend from that number and you are done.
Just roll with it as is. This is not going to waste much time since the bounds are small. When you have some working code, move on. No need to mercilessly optimise code for no reason.
just because I started this as a fun puzzle, here's the code:
[Test]
public void TestDateTime() {
var start = DateTime.Now.Date;
var end = DateTime.Now.Date.AddDays(35);
var workdays = (end - start).Days - ((end - start).Days/7)*2
- (((end - start).Days%7==0)?0:(((int)start.DayOfWeek==0)?1:Math.Max(Math.Min((int)start.DayOfWeek + (end - start).Days%7 - 6, 2), 0)));
new []{DateTime.Now.AddDays(19), DateTime.Now.AddDays(20)}.ToList().ForEach(
x => { if (x.DayOfWeek != DayOfWeek.Saturday && x.DayOfWeek != DayOfWeek.Sunday) workdays--; });
Console.Out.WriteLine("workdays = {0}", workdays);
}
Christmas day and Boxing day are included as holidays.