The datetime data type

The datetime data type represents an instant in time, typically expressed as a date and time of day. Values range from 00:00:00 (midnight), January 1, 0001 Anno Domini (Common Era) through 11:59:59 P.M., December 31, 9999 A.D. (C.E.) in the Gregorian calendar.

Time values are measured in 100-nanosecond units called ticks, and a particular date is the number of ticks since 12:00 midnight, January 1, 0001 A.D. (C.E.) in the GregorianCalendar calendar (excluding ticks that would be added by leap seconds). For example, a ticks value of 31241376000000000 represents the date, Friday, January 01, 0100 12:00:00 midnight. This is sometimes called "a moment in linear time".

The datetime and date data types are equivalent.


A datetime value in Kusto is always in the UTC time zone. If displaying datetime values in other time zones is required, use datetime_utc_to_local() or datetime_local_to_utc().

datetime literals

To specify a datetime literal, use one of the following syntax options:

Syntax Description Example
datetime( hour:minute:second.milliseconds) A date and time in UTC format. datetime(2015-12-31 23:59:59.9)
datetime( A date in UTC format. datetime(2015-12-31)
datetime() Returns the current time.
datetime(null) Represents the null value.

Learn more about syntax conventions.

The now() and ago() special functions

Kusto provides two special functions, now() and ago(), to allow queries to reference the time at which the query starts execution.

Supported formats

There are several formats for datetime that are supported as datetime() literals and the todatetime() function.


It is strongly recommended to use only the ISO 8601 formats.

ISO 8601

Format Example
%Y-%m-%dT%H:%M:%s%z 2014-05-25T08:20:03.123456Z
%Y-%m-%dT%H:%M:%s 2014-05-25T08:20:03.123456
%Y-%m-%dT%H:%M 2014-05-25T08:20
%Y-%m-%d %H:%M:%s%z 2014-11-08 15:55:55.123456Z
%Y-%m-%d %H:%M:%s 2014-11-08 15:55:55
%Y-%m-%d %H:%M 2014-11-08 15:55
%Y-%m-%d 2014-11-08

RFC 822

Format Example
%w, %e %b %r %H:%M:%s %Z Sat, 8 Nov 14 15:05:02 GMT
%w, %e %b %r %H:%M:%s Sat, 8 Nov 14 15:05:02
%w, %e %b %r %H:%M Sat, 8 Nov 14 15:05
%w, %e %b %r %H:%M %Z Sat, 8 Nov 14 15:05 GMT
%e %b %r %H:%M:%s %Z 8 Nov 14 15:05:02 GMT
%e %b %r %H:%M:%s 8 Nov 14 15:05:02
%e %b %r %H:%M 8 Nov 14 15:05
%e %b %r %H:%M %Z 8 Nov 14 15:05 GMT

RFC 850

Format Example
%w, %e-%b-%r %H:%M:%s %Z Saturday, 08-Nov-14 15:05:02 GMT
%w, %e-%b-%r %H:%M:%s Saturday, 08-Nov-14 15:05:02
%w, %e-%b-%r %H:%M %Z Saturday, 08-Nov-14 15:05 GMT
%w, %e-%b-%r %H:%M Saturday, 08-Nov-14 15:05
%e-%b-%r %H:%M:%s %Z 08-Nov-14 15:05:02 GMT
%e-%b-%r %H:%M:%s 08-Nov-14 15:05:02
%e-%b-%r %H:%M %Z 08-Nov-14 15:05 GMT
%e-%b-%r %H:%M 08-Nov-14 15:05


Format Example
%Y-%n-%e %H:%M:%s 2014-11-08 15:05:25
%Y-%n-%e %H:%M:%s %Z 2014-11-08 15:05:25 GMT
%Y-%n-%e %H:%M 2014-11-08 15:05
%Y-%n-%e %H:%M %Z 2014-11-08 15:05 GMT
%Y-%n-%eT%H:%M:%s 2014-11-08T15:05:25
%Y-%n-%eT%H:%M:%s %Z 2014-11-08T15:05:25 GMT
%Y-%n-%eT%H:%M 2014-11-08T15:05
%Y-%n-%eT%H:%M %Z 2014-11-08T15:05 GMT