I have to add 15 minutes to the current time and set it to a DateTime object in C#. If my current time is say 11:50 PM, and 15 minutes is added, the hour part becomes 24 and is causing the following error: "Hour, Minute, and Second parameters describe an un-representable DateTime."
public static DateTime NewTime(this DateTime dateTime)
{
int hour = dateTime.Hour;
int minute = dateTime.Minute;
if (minute > 0)
{
minute = dateTime.Minute + (15);
if (minute >= 60)
{
hour = hour + 1;
minute = 0;
}
}
return new DateTime(dateTime.Year, dateTime.Month,
dateTime.Day, hour, minute, 0);
}
Thanks
Your logic does not make sense, you are only adding minutes if the minutes are greater than 0 so what happens if they are 0?
To add time use the methods built into the type definition, no need to reinvent the wheel. Example:
public static DateTime Add15Minutes(this DateTime dateTime)
{
return dateTime.AddMinutes(15);
}
You are checking for an overflow on the minute attribute, but not the hour attribute. You could check for an overflow on the hour attribute like this:
public static DateTime NewTime(this DateTime dateTime)
{
int hour = dateTime.Hour;
int minute = dateTime.Minute;
var day = dateTime.Day;
if (minute > 0)
{
minute = dateTime.Minute + (15);
if (minute >= 60)
{
hour = hour + 1;
minute = 0;
}
}
if (hour > 24) {
day += 1;
}
return new DateTime(dateTime.Year, dateTime.Month,
day, hour, minute, 0);
}
However, you will also run into problems with the overflow of days in a month, which is even more complicated to handle. Instead, just use the built in Add function:
public static DateTime NewTime(this DateTime dateTime)
{
return new dateTime.AddMinutes(15);
}
I think you are overthinking this maybe? DateTime already provides many support methods and this will probably do what you need without the need to create an extension method:
var myValue = new DateTime(2017,3,14,23,50,0);
var result = myValue.AddMinutes(15);
Related
I have been looking at Microsoft's documents and many stack overflow posts but none seem to answer my question. I want to know the simplest and easiest way to get an accurate week number for the current date in c#. I am pretty new to c# so please try and keep it simple. I have tried using:
int week = DateTime.Now.DayOfYear/7;
Console.WriteLine(week)
but on Monday (when I would like it to move onto the next week) it would show as the previous week.
Eg: If the date was 21/12/2020 it would say the current week is the 50th, which is 2 weeks off. Then on 22/12/2020 it would say it is the 51st week, which is 1 week off.
Please Help & Thanks in advance.
This is probably what you are looking for:
DateTime dt = new DateTime(2020, 12, 21);
Calendar cal = new CultureInfo("en-US").Calendar;
int week = cal.GetWeekOfYear(dt, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
Console.WriteLine(week);
You can change the CalendarWeekRule parameter to change the definition of the first week of the year:
FirstDay means that first week of the year can have any length. For example if the first day of the year was Sunday, it will be counted as week and the following Monday will be counted as part of second week.
FirstFourDayWeek means that the first week will be counted only if it mainly in this year. For example if the first day of the year will be Thursday the week will be counted, but if the year starts with Friday, the first week won't be counted.
FirstFullWeek means that the first week that will be counted will be the first full week of the year.
I have looked at this as well when I was writing an application in LotusNotes. From what I have found, the first week of the year must contain a Thursday. If you assume that Sunday is the last day of the week, then the lowest date for Sunday has to be the 4th. With this is mind (and I am very new to C# and all the intricacies) I wrote this code which will give you the week number of any given date and also the number of weeks for this year and the previous. #
public class DateCalculations
{
private readonly DateTime _weekDate;
private DateTime ThisSunday => GetSundayDate(_weekDate);
private DateTime FirstDay_ThisYear => DateTime.Parse($"01/01/{ ThisSunday.Year }");
private DateTime FirstDay_LastYear => DateTime.Parse($"01/01/{ ThisSunday.Year - 1 }");
private DateTime FirstDay_NextYear => DateTime.Parse($"01/01/{ ThisSunday.Year + 1 }");
private DateTime FirstSunday_ThisYear => GetSundayDate_WeekOne(FirstDay_ThisYear);
private DateTime FirstSunday_LastYear => GetSundayDate_WeekOne(FirstDay_LastYear);
private DateTime FirstSunday_NextYear => GetSundayDate_WeekOne(FirstDay_NextYear);
public DateCalculations(string weekDate)
{
if (DateTime.TryParse(weekDate, out _weekDate))
{
return;
}
else
{
throw new Exception("Incorrect date has been supplied");
}
}
private bool IsDateInFirstWeek(DateTime suppliedDate)
{
var output = false;
// First week must contain a Thursday, so lowest Sunday date possible is the 4th
if (suppliedDate.Day >= 4)
{
output = true;
}
return output;
}
private DateTime GetSundayDate(DateTime suppliedDate)
{
var checkDay = suppliedDate;
//Check if the day of the supplied date is a Sunday
while (checkDay.DayOfWeek != DayOfWeek.Sunday)
{
checkDay = checkDay.AddDays(1);
}
return checkDay;
}
private DateTime GetSundayDate_WeekOne(DateTime suppliedDate)
{
var checkDay = GetSundayDate(suppliedDate);
if (IsDateInFirstWeek(checkDay) == false)
{
checkDay = checkDay.AddDays(7);
}
return checkDay;
}
public int WeekNumber()
{
var output = 0;
if (ThisSunday == FirstSunday_ThisYear)
{
output = 1;
}
else if(ThisSunday > FirstSunday_ThisYear)
{
TimeSpan daysBetween = ThisSunday - FirstSunday_ThisYear;
output = (daysBetween.Days/7) + 1;
}
else
{
TimeSpan daysBetween = ThisSunday - FirstSunday_LastYear;
output = (daysBetween.Days / 7) + 1;
}
return output;
}
public int TotalWeeksThisYear()
{
TimeSpan daysBetween = FirstSunday_NextYear - FirstSunday_ThisYear;
return (daysBetween.Days / 7);
}
public int TotalWeeksLastYear()
{
TimeSpan daysBetween = FirstSunday_ThisYear - FirstSunday_LastYear;
return (daysBetween.Days / 7);
}
}
My console was used to test
class Program
{
static void Main()
{
var test = new DateCalculations("2021-01-03");
var weekNumber = test.WeekNumber();
var totalWeeks = test.TotalWeeksThisYear();
var pastWeeks = test.TotalWeeksLastYear();
Console.ReadLine();
}
}
The date format can be any string representation of a date (English or American)
Hope this helps. It may need refactoring though :)
Built on top of this answer: by #bunny4
But not everyone is located in the US or might have to support several cultures.
Use this solution to support a cultural defined week rule and first-Day rule.. e.g. Denmark has "FirstFourDayWeek" rule for weeks and "Monday" as first day of the week.
//for now, take the the current executing thread's Culture
var cultureInfo = Thread.CurrentThread.CurrentCulture;
//let's pick a date
DateTime dt = new DateTime(2020, 12, 21);
DayOfWeek firstDay = cultureInfo.DateTimeFormat.FirstDayOfWeek;
CalendarWeekRule weekRule = cultureInfo.DateTimeFormat.CalendarWeekRule;
Calendar cal = cultureInfo.Calendar;
int week = cal.GetWeekOfYear(dt, weekRule, firstDay);
This question already has answers here:
AddBusinessDays and GetBusinessDays
(17 answers)
Closed 3 years ago.
I am trying to calculate a finishing date when adding a duration to a start date, but skipping weekends and holidays:
DateTime start = DateTime.Now;
TimeSpan duration = TimeSpan.FromHours(100);
List<DateTime> = //List of holidays
DateTime end = ?
For example if it is 11pm on a Friday and I add 2 hours, it would end on 1am Monday morning.
Is there a neat way of doing this?
I have a temporary fix which increments the time by an hour and checks the day of the week, but it is very inefficient.
Original Idea (untested):
public static DateTime calEndDate(DateTime start, TimeSpan duration, List<DateTime> holidays)
{
var startDay = start.Day;
var i = 0;
var t = 0;
while (TimeSpan.FromHours(t) < duration)
{
var date = start.Add(TimeSpan.FromHours(i));
if (date.DayOfWeek.ToString() != "Saturday" && date.DayOfWeek.ToString() != "Sunday") //and something like !holidays.contains(start)
{
t++;
}
i++;
}
return start.Add(TimeSpan.FromHours(t));
}
}
However is needs to run over 100 times for different start dates/durations on one asp.net page load. I don't know how to benchmark it, but it doesn't seem like an elegant solution?
Here's an algorithm I'd try.
I'm on my phone, and I'll get it wrong, but you should see the logic...
var end = start;
var timeToMidnight = start.Date.AddDays(1) -start;
if ( duration < timeToMidnight ) return start + duration;
end = endMoment + timeToMidnight;
duration = duration - timeToMidnight;
//Helper method
bool IsLeisure(Datetime dt) => (dt.DayOfWeek == DayOfWeek.Saturday) || (dt.DayOfWeek == DayOfWeek.Sunday) || holidays.Any( h => h.Date == dt.Date);
//We're at the first tick of the new day. Let's move to a work day, if needed.
while(IsLeisure(end)) { end = end.AddDays(1); };
//Now let's process full days of 'duration'
while(duration >= TimeSpan.FromDays(1) ) {
end = end.AddDays(1);
if(!IsLeisure(end)) duration = duration - TimeSpan.FromDays(1);
}
//Finally, add the reminder
end = end + duration;
Note: you haven't specified the logic for when start moment is a weekend or a holiday.
Yes there is :
DateTime currentT = DateTime.Now;
DateTime _time_ = currentTime.AddHours(10);
Simple and neat.
Hi I was solving a problem to calculate some library fine based on difference in return date and due date in C#. Now there are some constraints to the problem like
if the return year is changed i.e. if the return year is greater than the due date calendar year then fine is 10000. e.g. due date "31/12/2015" and return date "01/01/2016" then also fine is 10000.
if the return month is changed then fine is 500 * number of months late.
if the return day is changed then fine is 15 * number of days late.
else fine is 0.
Now i wrote the function below:
static int CalcFine (int[] returnedOn, int[] dueOn) {
int returnD = returnedOn[0];
int returnM = returnedOn[1];
int returnY = returnedOn[2];
int dueD = dueOn[0];
int dueM = dueOn[1];
int dueY = dueOn[2];
if (returnY > dueY) {
return 10000;
} else if (returnY < dueY) {
return 0;
} else {
if (returnM > dueM) {
return (returnM - dueM) * 500;
} else if (returnM < dueM) {
return 0;
} else {
if (returnD > dueD) {
return (returnD - dueD) * 15;
} else {
return 0;
}
}
}
}
I read about the DateTime class in C# that has pretty neat functions that return the difference in two dates as total days, total minutes, etc. But given the constraint of Fine being different based on year, month and days, I am not sure if there is any other inbuilt function to solve the above problem. In short I am trying to find if there is another simple way to solve the above problem without using so many if-else's.
You can get the difference in days, hours or minutes.
DateTime fromdate = new DateTime(2012,1,1);
DateTime todate = DateTime.Now;
TimeSpan diff = todate - fromdate;
int differenceInDays = diff.Days;
If you want to try differently for your validations and business rules. Follow the below code
public double GetFineAmount(DateTime DueDate)
{
DateTime dt = DateTime.Now;
int yeardiff, monthdiff, daydiff;
yeardiff = dt.Year - DueDate.Year;
if (yeardiff > 0) return 10000;
monthdiff = dt.Month - DueDate.Month;
if (monthdiff > 0) return 500 * monthdiff;
daydiff = dt.Day - DueDate.Day;
if (daydiff > 0) return 15 * daydiff;
return 0;
}
Editted again.. changed string pattern. I guess I need some sleep...
static int CalcFine (string returnedOn, string dueOn)
{
DateTime returnedDate = DateTime.ParseExact(
returnedOn, "d M yyyy", CultureInfo.InvariantCulture);
DateTime dueDate = DateTime.ParseExact(
dueOn, "d M yyyy", CultureInfo.InvariantCulture);
if (returnedDate < dueDate)
return 0;
if (returnedDate.Year > dueDate.Year)
return 10000;
if (returnedDate.Month > dueDate.Month)
return 500 * (returnedDate.Month - dueDate.Month);
if (returnedDate.Day > dueDate.Day)
return 15 * (returnedDate.Day - dueDate.Day);
else
return 0;
}
DateTime is a powerful tool. But you don't want to over-complicate this.
If you just find the difference between the two dates in days, the equation becomes a lot easier to manage versus trying to subtract dates.
static int CalcFine(DateTime returnedOn, DateTime dueOn)
{
TimeSpan dateDiff = (returnedOn - dueOn);
int TotalDays = dateDiff.Days;
if (TotalDays >= 365)
{
return 10000;
}
else if(TotalDays < 365 && TotalDays > 30 && TotalDays % 30 > 1)
{
return (500 * (TotalDays % 30));
}
else if(TotalDays < 30 && TotalDays > 0)
{
return 15 * TotalDays;
}
else
{
return 0;
}
}
Suppose night time is set from 20.30h till 6.15h(AM). These 2 parameters are user-scoped variables.
Suppose you have an arrival date and a departure date which can span from a few minutes to more than one total day.
How do you calculate the total hours of night time?
public static double CalculateTotalNightTimeHours(DateTime arrival,
DateTime departure,
int nightTimeStartHour,
int nightTimeStartMinute,
int nightTimeEndHour,
int nightTimeEndMinute)
{
//??
}
EDIT: I understand this may be no straight forward yes/no answer, but maybe someone has an elegant solution for this problem.
To answer the comments : I indeed want to calculate the total number of hours (or minutes) that fall between a user-editable night start and end time. I'm calculating visit time, and the first date is indeed the arrival parameter.
The code I had sofar :
DateTime nightStart = new DateTime( departure.Year, departure.Month, departure.Day,
nightTimeStartHour, nightTimeStartMinute, 0);
DateTime nightEnd = new DateTime( arrival.Year, arrival.Month, arrival.Day,
nightTimeEndHour, nightTimeEndMinute, 0);
if (arrival < nightEnd)
{
decimal totalHoursNight = (decimal)nightEnd.Subtract(arrival).TotalHours;
}
//...
Just because I was up for the challenge you should be able to use the following function with success. Please note that this is probably not the most efficient way to do it, but I did it this way so I could lay out the logic. I may decide to edit this as some point to improve it, but it should work fine as is.
It is also important to note a couple of assumptions here:
the 'end' parameter is always greater than the 'start' parameter (although we check that first thing anyway)
the night end parameters are earlier than the night start parameters (i.e. night time ends on the following day, but never as much as 24 hours later)
Daylight savings time does not exist! (this is a tricky concern, one important question to address is: if either your start or end time is at 01:30 on the day the clocks go back, how will you know if the time was recorded before or after the rollback? i.e is it the first or second time the clock has hit 01:30?)
with that in mind...
public static double Calc(DateTime start, DateTime end, int startHour, int startMin, int endHour, int endMin)
{
if (start > end)
throw new Exception();//or whatever you want to do
//create timespans for night hours
TimeSpan nightStart = new TimeSpan(startHour, startMin, 0);
TimeSpan nightEnd = new TimeSpan(endHour, endMin, 0);
//check to see if any overlapping actually happens
if (start.Date == end.Date && start.TimeOfDay >= nightEnd && end.TimeOfDay <= nightStart)
{
//no overlapping occurs so return 0
return 0;
}
//check if same day as will process this differently
if (start.Date == end.Date)
{
if (start.TimeOfDay > nightStart || end.TimeOfDay < nightEnd)
{
return (end - start).TotalHours;
}
double total = 0;
if (start.TimeOfDay < nightEnd)
{
total += (nightEnd - start.TimeOfDay).TotalHours;
}
if(end.TimeOfDay > nightStart)
{
total += (end.TimeOfDay - nightStart).TotalHours;
}
return total;
}
else//spans multiple days
{
double total = 0;
//add up first day
if (start.TimeOfDay < nightEnd)
{
total += (nightEnd - start.TimeOfDay).TotalHours;
}
if (start.TimeOfDay < nightStart)
{
total += ((new TimeSpan(24, 0, 0)) - nightStart).TotalHours;
}
else
{
total += ((new TimeSpan(24, 0, 0)) - start.TimeOfDay).TotalHours;
}
//add up the last day
if (end.TimeOfDay > nightStart)
{
total += (end.TimeOfDay - nightStart).TotalHours;
}
if (end.TimeOfDay > nightEnd)
{
total += nightEnd.TotalHours;
}
else
{
total += end.TimeOfDay.TotalHours;
}
//add up any full days
int numberOfFullDays = (end - start).Days;
if (end.TimeOfDay > start.TimeOfDay)
{
numberOfFullDays--;
}
if (numberOfFullDays > 0)
{
double hoursInFullDay = ((new TimeSpan(24, 0, 0)) - nightStart).TotalHours + nightEnd.TotalHours;
total += hoursInFullDay * numberOfFullDays;
}
return total;
}
}
You can then call it something like this:
double result = Calc(startDateTime, endDateTime, 20, 30, 6, 15);
Basically you'll want to calculate when night starts and ends. Then compare those to the arrival and departure dates to see if you arrival after night starts or depart before it ends to get the values you need to subtract to determine the total night hours. Then you need to continue to calculate this for each day until the start time for night is pass the departure date. Here's my solution for that.
public static double CalculateTotalNightTimeHours(
DateTime arrival,
DateTime departure,
int nightTimeStartHour,
int nightTimeStartMinute,
int nightTimeEndHour,
int nightTimeEndMinute)
{
if (arrival >= departure)
return 0;
var nightStart = arrival.Date.AddHours(nightTimeStartHour).AddMinutes(nightTimeStartMinute);
var nightEnd = nightStart.Date.AddDays(1).AddHours(nightTimeEndHour).AddMinutes(nightTimeEndMinute);
double nightHours = 0;
while (departure > nightStart)
{
if (nightStart < arrival)
nightStart = arrival;
if (departure < nightEnd)
nightEnd = departure;
nightHours += (nightEnd - nightStart).TotalHours;
nightStart = nightStart.Date.AddDays(1).AddHours(nightTimeStartHour).AddMinutes(nightTimeStartMinute);
nightEnd = nightStart.Date.AddDays(1).AddHours(nightTimeEndHour).AddMinutes(nightTimeEndMinute);
}
return nightHours;
}
You'd probably also want to add checking to make sure the start and end hours are within range. This also assumes that night starts on one day and ends on the next, so if you wanted night to end before midnight you'd have to do something else.
Interesting issue I'm facing and I just can't come up with an algorim to calculate.
Basically, what I want is to calculate a DateTime based on DateTime.Now.AddMinutes() but the Adding of minutes should take into consideration Working Hours and weekends.
In other words, if the time is currently 16:50 and i add 20 minutes, the method should return a DateTime for tomorrow morning at 08:10 (if tomorrow is not a weekend day).
I've started with some logic, but it's not complete. Does anyone have a sample which can save me a few hours of coding? This is what i've got so far:
public DateTime CalculateSLAFromNow(int minutes)
{
DateTime now = DateTime.Now;
TimeSpan slatimeaddedon = CalculateToNextWeekDay(DateTime.Now);
TimeSpan finalMinutesAddedon = slatimeaddedon.Add(new TimeSpan(0, minutes, 0));
DateTime SLATime = DateTime.Now.AddMinutes(slatimeaddedon.TotalMinutes);
return SLATime;
}
private TimeSpan CalculateToNextWeekDay(DateTime dt)
{
//Calculate.
}
public static DateTime CalculateSLAFromNow(int minutes)
{
double days = (double)minutes / 540;
DateTime now = DateTime.Now;
DateTime later = now;
while (days >= 1)
{
later = later.AddDays(1);
if (later.DayOfWeek == DayOfWeek.Saturday)
{
later = later.AddDays(2);
}
days--;
}
days = days * 540;
later = later.AddMinutes(days);
if (later.Hour > 17)
{
later = later.AddHours(15);
}
if (later.DayOfWeek == DayOfWeek.Saturday)
{
later = later.AddDays(2);
}
else if(later.DayOfWeek == DayOfWeek.Sunday)
{
later = later.AddDays(1);
}
return later;
}
There now it accounts for any number of minutes added (not the prettiest code, but it works)
Ok. Friend of mine wrote the following which works 100%. Thanks J for this. Herewith the complete solution:
private static DateTime DoCalculation(DateTime startDate, int minutes)
{
if (startDate.DayOfWeek == DayOfWeek.Sunday)
{
// if the input date is a sunday, set the actual SLA start date to the following monday morning 7:00AM
startDate = startDate.AddHours(24);
startDate = new DateTime(startDate.Year, startDate.Month, startDate.Day, 7, 0, 0);
}
else if (startDate.DayOfWeek == DayOfWeek.Saturday)
{
// if the input date is a saturday, set the actual SLA start date to the following monday morning 7:00AM
startDate = startDate.AddHours(48);
startDate = new DateTime(startDate.Year, startDate.Month, startDate.Day, 7, 0, 0);
}
DateTime resultDate = startDate;
for (int i = 0; i < minutes; i++)
{
resultDate = resultDate.AddMinutes(1);
// it is 5PM and time to go home
if (resultDate.Hour >= 17)
{
// if tomorrow is saturday
if (resultDate.AddDays(1).DayOfWeek == DayOfWeek.Saturday)
{
//add 48 hours to get us through the whole weekend
resultDate = resultDate.AddHours(48);
}
// add 14 hours to get us to next morning
resultDate = resultDate.AddHours(14);
}
}
return resultDate;
}