Reputation: 5699
Assume I have a DateTime:
DateTime datetime(2013,11,08,17,45,23,300);//2013:11:08 17:45:23:300
I want to truncate this DateTime by differenct accuracy and return the minimum DateTime like this:
Year: 2013:01:01 00:00:00:000
Quarter: 2013:10:01 00:00:00:000 //Oct is first month of that quarter
Month: 2013:11:01 00:00:00:000
Week: 2013:11:03 00:00:00:000 // 3rd is Sunday of that week
Day: 2013:11:08 00:00:00:000
Hours 2013:11:08 17:00:00:000
Minute: 2013:11:08 17:45:00:000
Second: 2013:11:08 17:45:23:000
I know you can do it by changing different part of the DateTime, is there a better way to do it? or is there already a build in function in .net which I don't know?
Upvotes: 4
Views: 1567
Reputation: 272
There's not one that I know of, but this should do the trick:
public enum Accuracy { Year, Quarter, Month, Week, Day, Hour, Minute, Second};
private static DateTime TruncateDate(DateTime inDate, Accuracy accuracy){
switch (accuracy)
{
case Accuracy.Year:
return new DateTime(inDate.Year, 1, 1);
case Accuracy.Quarter:
int i = inDate.Month % 3;
return new DateTime(inDate.Year, inDate.Month - i + 1, 1);
case Accuracy.Month:
return new DateTime(inDate.Year, inDate.Month, 1);
case Accuracy.Week:
return new DateTime(inDate.Year, inDate.Month, inDate.Day).AddDays(-(int)inDate.DayOfWeek);
case Accuracy.Day:
return new DateTime(inDate.Year, inDate.Month, inDate.Day);
case Accuracy.Hour:
return new DateTime(inDate.Year, inDate.Month, inDate.Day, inDate.Hour, 0, 0);
case Accuracy.Minute:
return new DateTime(inDate.Year, inDate.Month, inDate.Day, inDate.Hour, inDate.Minute, 0);
case Accuracy.Second:
return new DateTime(inDate.Year, inDate.Month, inDate.Day, inDate.Hour, inDate.Minute, inDate.Second);
default:
throw new ArgumentOutOfRangeException("accuracy");
}
}
Edit: corrected for when Sunday is in a different month.
Upvotes: 4
Reputation: 61982
Based on my own comment:
public static DateTime Truncate(this DateTime dt, TimeSpan resolution)
{
return new DateTime(dt.Ticks - dt.Ticks % resolution.Ticks);
}
Edit:
Example use: var truncated = dt.Truncate(Timespan.FromHours(1.0));
As I said in that comment, this is not useful for stuff like years and quarters of a year whose lengths (mathematically) vary from instance to instance.
Upvotes: 3
Reputation: 1139
This creates a DateTime at midnight of Today. You can take any DateTime and call the 'Date' property to get rid of hours/minutes/seconds.
// 1/7/2014 12:00:00 AM
DateTime.Now.Date
From there to get a specific time like 5AM
var 5amDate = DateTime.Now.Date.AddHours(5)
// 1/7/2014 5:00:00 AM
Upvotes: 0