README.md

Date Math

This is a .NET library for parsing "date math" as seen in Elasticsearch. To find out more about date math, read this and this.

You can use this library for setting default report parameters, e.g:

Range Description	Start	End
last 10 days	now-10d	now
month to date	now/M	now
year to date	now/y	now
a sliding 60 day window	now-30d	now+30d

Basic Usage

Let now be 2016-12-31 1 PM:

DateMath.Parse("now","yyyy-MM-dd h tt"); // 2016-12-31 1 PM
DateMath.Parse("now+11h", "yyyy-MM-dd h tt"); // 2017-01-01 12 AM
DateMath.Parse("now-13h+1y+1d-1s", "yyyy-MM-dd HH:mm:ss"); // 2017-12-31 23:59:59
DateMath.Parse("now/d", "yyyy-MM-dd HH:mm:ss.fff"); // 2016-12-31 00:00:00.000

If you want to know if your string was parsed successfully:

DateTime date;
if(DateMath.TryParse("now+11h", out date)){
    // do something with date
}

If you already have a date:

DateTime date = new DateTime(2016,12,31,9,30,2);
var newYears = DateMath.Apply(date, "+1d/y");

See tests for other usage.