I have a Time class containing custom + logic, where an exception is thrown is the Hours become higher than 23. I also have a Workshift class which has a Day property and where I'd like to use Time as properties, but with a minor difference in addition logic: when the hours go over 23, change the day, thus I've created a WorkingTime class which inherits from Time, but changes the operator's behavior. At first I thought I could pass a Workshift reference into the WorkingTime class and just control it from there, but, aside from this (most likely) being a catastrophic design... My problem is: I don't know how to change the day, because overloading operator requires a static Workshift reference, and the it cannot be static for this to work as intended. How do I make that happen?
Here's the code I've come up with so far:
public class Time
{
public ushort Hours { get; private set; }
public ushort Minutes { get; private set; }
public Time(ushort hours, ushort minutes)
{
if (hours > 23 || minutes > 59)
{
throw new ArgumentException("Invalid time specified");
}
Hours = hours;
Minutes = minutes;
}
public static Time operator +(Time a, Time b)
{
var hoursResult = a.Hours + b.Hours;
var minutesResult = a.Minutes + b.Minutes;
if (minutesResult > 59)
{
hoursResult += 1;
minutesResult = minutesResult - 60;
}
if (hoursResult > 23)
throw new Exception("Too many hours!");
ushort hours = (ushort)hoursResult;
ushort minutes = (ushort)minutesResult;
return new Time(hours, minutes);
}
}
public class Workshift
{
public Day Day { get; set; }
public WorkingTime StartHour { get; set; }
public WorkingTime EndHour { get; set; }
private class WorkingTime : Time
{
private Workshift _workshiftReference;
public WorkingTime(ushort hours, ushort minutes, Workshift workshift) : base(hours, minutes)
{
_workshiftReference = workshift;
}
public static WorkingTime operator +(WorkingTime a, WorkingTime b)
{
var hoursResult = a.Hours + b.Hours;
var minutesResult = a.Minutes + b.Minutes;
if (minutesResult > 59)
{
hoursResult += 1;
minutesResult = minutesResult - 60;
}
if (hoursResult > 23)
_workshiftReference.Day++; //how do I achieve this?
ushort hours = (ushort)hoursResult;
ushort minutes = (ushort)minutesResult;
return new WorkingTime(hours, minutes, _workshiftReference);
}
}
}
The high-level goal is to, for example, set day from Friday to Saturday when someone tries to add 3 hours to a Time which has 22 Hours and 30 Minutes. So {Friday, 22, 30} becomes {Saturday, 1, 30}.
Because the overloaded WorkingTime operator is static, when it is called it won't know what _workshiftReference is as it is tied to a member of an non static object.
You could make working time static and give the day field get/set functions. Or you could not overload the + operator and make a function with three parameters that takes (Time A, Time B, Workshift work).
It looks like you are adding all these nested classes just to make the overloaded + operator work, so I would maybe re-look into how your implementing what you are trying to do. Maybe just regular functions would work better.
The structure
public struct Tick : IEquatable<Tick>
{
public DateTime date;
public decimal price;
public int volume;
public Tick(DateTime date, decimal price, int volume)
{
this.date = date;
this.price = price;
this.volume = volume;
}
public override bool Equals(object obj)
{
var other = (Tick)obj;
return this.date == other.date && this.price == other.price && this.volume == other.volume;
}
public bool Equals(Tick other)
{
return this.date == other.date && this.price == other.price && this.volume == other.volume;
}
}
is changed in this test:
[Test]
public void MarshalDoesntRoundsDateTime() {
for (int i = 0; i < 1000; i++)
{
var now = new Tick(DateTime.Now.AddSeconds(i), i, i);
var now2 = now;
var ticks = new Tick[1];
unsafe
{
fixed (Tick* ptr = &ticks[0])
{
Marshal.StructureToPtr(now2, (IntPtr)ptr, false);
now2 = (Tick)Marshal.PtrToStructure((IntPtr)ptr, typeof(Tick));
Assert.AreEqual(now.date.Ticks, now2.date.Ticks);
}
}
}
}
Expected: 635719676058860752
But was: 635719676058860000
What is going on? Why DateTime is rounded after marshalling? Is this documented somewhere?
Marshal.StructureToPtr() is intended to marshal data for unmanaged code. There is are multiple "standards" for dates in native code, none that are close in range and accuracy to DateTime. The CLR designers went for the COM interop standard, also exposed by DateTime.ToOADate().
As you can tell from the Reference Source, it can be no more accurate than 1 msec. DateTime is accurate to 0.1 usec. Inevitably the last 4 digits you are looking at must be 0.
It is not clear why you are doing this or why it matters. Guessing, do keep in mind that Marshal.StructureToPtr() only seems like an attractive way to serialize .NET data.
The true error is that DateTime shouldn't be marshalable... If you try to Marshal it directly you get an ArgumentException.
If you really really want to Marshal a DateTime (and I don't even want to know why, considering it is a semi-proprietary format of .NET), you could:
public long date;
public DateTime Date
{
get
{
return DateTime.FromBinary(date);
}
set
{
date = value.ToBinary();
}
}
I want to write an extension method that adds one day to a Nullable DateTime, but modifies the date itself.
I want to use it as follows:
someDate.AddOneDay();
This directly changes the value of someDate.
The code I initially wrote was:
public static DateTime? AddOneDay(this DateTime? date)
{
if (date.HasValue)
{
date.Value = date.Value.AddDays(1);
}
return null;
}
but this doesn't work since the reference is changed thus calling it this way
won't change the value of someDate.
Is there a way to achieve this and avoid code like:
someDate = someDate.AddOneDay();
Also I was thinking for some setter of the DateTime properties, but they don't have any..
public int Day { get; }
public int Month { get; }
public int Year { get; }
You can't DateTime is immutable, and should stay that way.
Just do:
someDate = someDate.AddOneDay();
And if you want to be more specific, you could rename your function to:
DateTime? someDate = someDate.AddOneDayOrDefault();
old school %)
public static void AddOneDay(ref DateTime date)
{
if (date != null) date = date.AddDays(1);
}
usage:
DateTime date = DateTime.Now;
AddOneDay(ref date);
UPD
one line version of method:
public static void AddOneDay(ref DateTime date) { date = date.AddDays(1); }
C# does support a similar feature, even for mutable values, which is the use of += on nullable values:
DateTime? date = GetDate();
var oneDay = TimeSpan.FromDays(1);
date += oneDay;
I need to remove time portion of date time or probably have the date in following format in object form not in the form of string.
06/26/2009 00:00:00:000
I can not use any string conversion methods as I need the date in object form.
I tried first converting the DateTime to a string, remove the time specific date from it, but it adds 12:00:00 AM as soon as I convert it back to DateTime object back again.
Use the Date property:
var dateAndTime = DateTime.Now;
var date = dateAndTime.Date;
The date variable will contain the date, the time part will be 00:00:00.
You can use format strings to give the output string the format you like.
DateTime dateAndTime = DateTime.Now;
Console.WriteLine(dateAndTime.ToString("dd/MM/yyyy")); // Will give you smth like 25/05/2011
Read more about Custom date and time format strings.
Use the method ToShortDateString. See the documentation http://msdn.microsoft.com/en-us/library/system.datetime.toshortdatestring.aspx
var dateTimeNow = DateTime.Now; // Return 00/00/0000 00:00:00
var dateOnlyString = dateTimeNow.ToShortDateString(); //Return 00/00/0000
Have a look at the DateTime.Date property.
Gets the date component of this instance.
The Date property will return the date at midnight.
One option could be to get the individual values (day/month/year) separately and store it in the type you want.
var dateAndTime = DateTime.Now;
int year = dateAndTime.Year;
int month = dateAndTime.Month;
int day = dateAndTime.Day;
string.Format("{0}/{1}/{2}", month, day, year);
None of the above answers solved my problem on winforms.
the easiest way to reach ONLY date is the simple function in Datetime:
DateTime dt = DateTime.now;
String BirthDate = dt.ToShortDateString();
You will only have date in Birthday string .
Try to make your own Structure for that. DateTime object will have date and time both
You can't. A DateTime in .NET always have a time, defaulting to 00:00:00:000. The Date property of a DateTime is also a DateTime (!), thus having a time defaulting to 00:00:00:000 as well.
This is a shortage in the .NET Framework, and it could be argued that DateTime in .NET violates the Single Responsibility Principle.
The easiest way is something like this and it will return only the date:
var date = DateTime.Now.ToShortDateString();
Here is another method using String.Format
DateTime todaysDate = DateTime.UtcNow;
string dateString = String.Format("{0:dd/MM/yyyy}", todaysDate);
Console.WriteLine("Date with Time: "+ todaysDate.ToString());
Console.WriteLine("Date Only : " + dateString);
Output:
Date with Time: 9/4/2016 11:42:16 AM
Date Only : 04/09/2016
This also works if the Date Time is stored in database.
For More Date and Time formatting check these links:
Reference 1
Reference 2
Hope helps.
DateTime.Date
var newDate = DateTime.Now; //newDate.Date property is date portion of DateTime
This way of get only date without time
DateTime date = DateTime.Now;
string Strdateonly = date.ToString("d");
Output = 5/16/2015
Use date.ToShortDateString() to get the date without the time component
var date = DateTime.Now
var shortDate = date.ToShortDateString() //will give you 16/01/2019
use date.ToString() to customize the format of the date
var date = DateTime.Now
var shortDate = date.ToString('dd-MMM-yyyy') //will give you 16-Jan-2019
Since .NET 6 / C# 10 you can do this:
var dateOnly = DateOnly.FromDateTime(dateTime);
I wrote a DateOnly structure. This uses a DateTime under the skin but no time parts are exposed publically:
using System;
public struct DateOnly : IComparable, IFormattable, IComparable<DateOnly>, IEquatable<DateOnly>
{
private DateTime _dateValue;
public int CompareTo(object obj)
{
if (obj == null)
{
return 1;
}
DateOnly otherDateOnly = (DateOnly)obj;
if (otherDateOnly != null)
{
return ToDateTime().CompareTo(otherDateOnly.ToDateTime());
}
else
{
throw new ArgumentException("Object is not a DateOnly");
}
}
int IComparable<DateOnly>.CompareTo(DateOnly other)
{
return this.CompareToOfT(other);
}
public int CompareToOfT(DateOnly other)
{
// If other is not a valid object reference, this instance is greater.
if (other == new DateOnly())
{
return 1;
}
return this.ToDateTime().CompareTo(other.ToDateTime());
}
bool IEquatable<DateOnly>.Equals(DateOnly other)
{
return this.EqualsOfT(other);
}
public bool EqualsOfT(DateOnly other)
{
if (other == new DateOnly())
{
return false;
}
if (this.Year == other.Year && this.Month == other.Month && this.Day == other.Day)
{
return true;
}
else
{
return false;
}
}
public static DateOnly Now()
{
return new DateOnly(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day);
}
public static bool TryParse(string s, ref DateOnly result)
{
DateTime dateValue = default(DateTime);
if (DateTime.TryParse(s, out dateValue))
{
result = new DateOnly(dateValue.Year, dateValue.Month, dateValue.Day);
return true;
}
else
{
return false;
}
}
public static DateOnly Parse(string s)
{
DateTime dateValue = default(DateTime);
dateValue = DateTime.Parse(s);
return new DateOnly(dateValue.Year, dateValue.Month, dateValue.Day);
}
public static DateOnly ParseExact(string s, string format)
{
CultureInfo provider = CultureInfo.InvariantCulture;
DateTime dateValue = default(DateTime);
dateValue = DateTime.ParseExact(s, format, provider);
return new DateOnly(dateValue.Year, dateValue.Month, dateValue.Day);
}
public DateOnly(int yearValue, int monthValue, int dayValue) : this()
{
Year = yearValue;
Month = monthValue;
Day = dayValue;
}
public DateOnly AddDays(double value)
{
DateTime d = new DateTime(this.Year, this.Month, this.Day);
d = d.AddDays(value);
return new DateOnly(d.Year, d.Month, d.Day);
}
public DateOnly AddMonths(int months)
{
DateTime d = new DateTime(this.Year, this.Month, this.Day);
d = d.AddMonths(months);
return new DateOnly(d.Year, d.Month, d.Day);
}
public DateOnly AddYears(int years)
{
DateTime d = new DateTime(this.Year, this.Month, this.Day);
d = d.AddYears(years);
return new DateOnly(d.Year, d.Month, d.Day);
}
public DayOfWeek DayOfWeek
{
get
{
return _dateValue.DayOfWeek;
}
}
public DateTime ToDateTime()
{
return _dateValue;
}
public int Year
{
get
{
return _dateValue.Year;
}
set
{
_dateValue = new DateTime(value, Month, Day);
}
}
public int Month
{
get
{
return _dateValue.Month;
}
set
{
_dateValue = new DateTime(Year, value, Day);
}
}
public int Day
{
get
{
return _dateValue.Day;
}
set
{
_dateValue = new DateTime(Year, Month, value);
}
}
public static bool operator == (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() == aDateOnly2.ToDateTime());
}
public static bool operator != (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() != aDateOnly2.ToDateTime());
}
public static bool operator > (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() > aDateOnly2.ToDateTime());
}
public static bool operator < (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() < aDateOnly2.ToDateTime());
}
public static bool operator >= (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() >= aDateOnly2.ToDateTime());
}
public static bool operator <= (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() <= aDateOnly2.ToDateTime());
}
public static TimeSpan operator - (DateOnly aDateOnly1, DateOnly aDateOnly2)
{
return (aDateOnly1.ToDateTime() - aDateOnly2.ToDateTime());
}
public override string ToString()
{
return _dateValue.ToShortDateString();
}
public string ToString(string format)
{
return _dateValue.ToString(format);
}
public string ToString(string fmt, IFormatProvider provider)
{
return string.Format("{0:" + fmt + "}", _dateValue);
}
public string ToShortDateString()
{
return _dateValue.ToShortDateString();
}
public string ToDbFormat()
{
return string.Format("{0:yyyy-MM-dd}", _dateValue);
}
}
This is converted from VB.NET, so apologies if some conversions are not 100%
I'm surprised no one has mentioned DateTime.Today
var date = DateTime.Today;
// {7/1/2014 12:00:00 AM}
See MSDN
If you are converting it to string, you can easily do it like this.
I'm taking date as your DateTime object.
date.ToString("d");
This will give you only the date.
You Can Try This for the Only Date From the Datetime
String.Format("{0:d/M/YYYY}",dt);
Where dt is the DateTime
Came across this post when trying to solve the original Q.
I am using Asp.Net and after some research I have found when you are binding to the value of the date in code behind, you can drop the time so it will not display on screen.
C#:
DateTime Today = DateTime.Now;
aspx:
<%: this.Today.ToShortDateString() %>
use
DateTime.Now.ToString("dd-MM-yyyy");
I know this is an old post with many answers, but I haven't seen this way of removing the time portion. Suppose you have a DateTime variable called myDate, with the date with time part. You can create a new DateTime object from it, without the time part, using this constructor:
public DateTime(int year, int month, int day);
Like this:
myDate = new DateTime(myDate.Year, myDate.Month, myDate.Day);
This way you create a new DateTime object based on the old one, with 00:00:00 as time part.
You can use this simple code below.
Code: DateTime.Now.ToShortDateString();
Ex.
Console.WriteLine(DateTime.Now.ToShortDateString());
This is for C#10 and above where now a DateOnly and TimeOnly format is available. Using below format, you can extract DateOnly from a DateTime format.
DateOnly myDateNoTime = DateOnly.FromDateTime(DateTime.Now);
string dt = myCalender.SelectedDate.ToString();
string date = dt.Remove(10);
displayDate.Content = date;
If you take date from calender, with this we also get time. Which is not required all time. Using this we can remove time from date.
in my experience none of the said solutions worked, maybe because I wanted to remove the time from extracted date from database, but the code below worked fine:
var date = target_date.Value.ToString("dd/MM/yyyy");
Declare the variable as a string.
example :
public string dateOfBirth ;
then assign a value like :
dateOfBirth = ((DateTime)(datetimevaluefromDB)).ToShortDateString();
This could be simply done this way:
var dateOnly = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day)
Create a struct that holds only the properties you want. Then an extension method to easily get that struct from an instance of DateTime.
public struct DateOnly
{
public int Day { get; set; }
public int Month { get; set; }
public int Year { get; set; }
}
public static class DateOnlyExtensions
{
public static DateOnly GetDateOnly(this DateTime dt)
{
return new DateOnly
{
Day = dt.Day,
Month = dt.Month,
Year = dt.Year
};
}
}
Usage
DateTime dt = DateTime.Now;
DateOnly result = dt.GetDateOnly();
To get only the date portion use the ToString() method,
example:
DateTime.Now.Date.ToString("dd/MM/yyyy")
Note:
The mm in the dd/MM/yyyy format must be capitalized
Add Date property to the DateTime variable
var dateTime = DateTime.Now
var onlyDate = dateTime.Date
Or You can use DataType annotation as well.
[DataType(DataType.Date)]
public DateTime dateTime {get; set;}
The DataType annotation is inside the System.ComponentModel.DataAnnotations namespace.
01.02.2010 0:00:00 -> 01.02.2010 anytime
01.02.2010 0:00:00 -> 01.02.2010 0:any minutes and seconds
so here is my date :
DateTime x;
it's
01.02.2010 0:00:00
as a string
x.Date.ToString()
here I compare date
DatarowsForOneDay = dt.Select("DailyRecTime= '" + x.ToString() + "'");
So how can I group by date + Hours without care about minutes and seconds.
You could write your own IEqualityComparer<DateTime> to only compare the parts of the DateTime you care about. LINQ's GroupBy has an overload that takes an IEqualityComparer. I had the same problem recently and did just that.
But you would have to call GroupBy before converting to strings. If you can't then you might want to create an IEqualityComparer<string> and parse the strings back to DateTime before comparing.
I don't have the original code with me right now. I re-typed this from memory and did not test it.
public class DateAndHourComparer : IEqualityComparer
{
public bool Equals(DateTime x, DateTime y)
{
var xAsDateAndHours = AsDateHoursAndMinutes(x);
var yAsDateAndHours = AsDateHoursAndMinutes(y);
return xAsDateAndHours.Equals(yAsDateAndHours);
}
private DateTime AsDateHoursAndMinutes(DateTime dateTime)
{
return new DateTime(dateTime.Year, dateTime.Month,
dateTime.Day, dateTime.Hour,
dateTime.Minute, 0);
}
public int GetHashCode(DateTime obj)
{
return AsDateHoursAndMinutes(obj).GetHashCode();
}
}
I never did the string based version, but it could use the above DateTime based code and look something like...
public class DateAndHourStringComparer : IEqualityComparer
{
private readonly DateAndHourComparer dateComparer = new DateAndHourComparer();
public bool Equals(string x, string y)
{
var xDate = DateTime.Parse(x);
var yDate = DateTime.Parse(y);
return dateComparer.Equals(xDate, yDate);
}
public int GetHashCode(string obj)
{
var date = DateTime.Parse(obj);
return dateComparer.GetHashCode(date);
}
}
I have not tested it, I did not add null checks or format checks. The code is meant to demonstrate the general idea.
You can pass a parameter with DateTime.ToString(string pattern).
More information # http://www.geekzilla.co.uk/View00FF7904-B510-468C-A2C8-F859AA20581F.htm.