CODEWITHSUNDEEP
c#.netdatetime
Lloyd Cotten
Lloyd Cotten

Reputation: 4556

Is there a better way to trim a DateTime to a specific precision?

What's the best way to trim a DateTime object to a specific precision? For instance, if I have a DateTime with a value of '2008-09-29 09:41:43', but I only want it's precision to be to the minute, is there any better way to do it than this?

private static DateTime TrimDateToMinute(DateTime date)
{
    return new DateTime(
        date.Year, 
        date.Month, 
        date.Day, 
        date.Hour, 
        date.Minute, 
        0);
}

What I would really want is to make it variable so that I could set its precision to the second, minute, hour, or day.

Upvotes: 71

Views: 40701

Answers (5)

rocketsarefast
rocketsarefast

Reputation: 4170

I like this method. Someone mentioned it was good to preserve the Date Kind, etc. This accomplishes that because you dont have to make a new DateTime. The DateTime is properly cloned from the original DateTime and it simply subtracts the remainder ticks.

public static DateTime FloorTime(DateTime dt, TimeSpan interval) 
{
  return dt.AddTicks(-1 * (dt.Ticks % interval.Ticks));
}

usage:

dt = FloorTime(dt, TimeSpan.FromMinutes(5)); // floor to the nearest 5min interval
dt = FloorTime(dt, TimeSpan.FromSeconds(1)); // floor to the nearest second
dt = FloorTime(dt, TimeSpan.FromDays(1));    // floor to the nearest day

Upvotes: 8

Bartek Szabat
Bartek Szabat

Reputation: 3014

static class Program
{
    //using extension method:
    static DateTime Trim(this DateTime date, long roundTicks)
    {
        return new DateTime(date.Ticks - date.Ticks % roundTicks, date.Kind);
    }

    //sample usage:
    static void Main(string[] args)
    {
        Console.WriteLine(DateTime.Now);
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerDay));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerHour));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerMillisecond));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerMinute));
        Console.WriteLine(DateTime.Now.Trim(TimeSpan.TicksPerSecond));
        Console.ReadLine();
    }

}

Upvotes: 126

Marcos Arruda
Marcos Arruda

Reputation: 742

There are some good solutions presented here, but when I need to do this, I simply do:

DateTime truncDate;
truncDate = date.Date; // trim to day
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:00:00}", date)); // trim to hour
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:mm}", date)); // trim to minute
truncDate = date.Date + TimeSpan.Parse(string.Format("{0:HH:mm:ss}", date)); // trim to second

Hope it helps.

Upvotes: 1

Rikalous
Rikalous

Reputation: 4574

You could use an enumeration

public enum DateTimePrecision
{
  Hour, Minute, Second
}

public static DateTime TrimDate(DateTime date, DateTimePrecision precision)
{
  switch (precision)
  {
    case DateTimePrecision.Hour:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, 0, 0);
    case DateTimePrecision.Minute:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, 0);
    case DateTimePrecision.Second:
      return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second);
    default:
      break;
  }
}

and expand as required.

Upvotes: 9

Gunarathinam
Gunarathinam

Reputation: 428

DateTime dt = new DateTime()
dt = dt.AddSeconds(-dt.Second)

Above code will trim seconds.

Upvotes: -2

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