The datetime data type

The datetime (date) 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".


A datetime value in Kusto is always in the UTC time zone. Displaying datetime values in other time zones is the responsibility of the user application that displays the data, not a property of the data itself. Should time zone values be required to be kept as a part of the data, a separate columns should be used (providing offset information relative to UTC).

datetime literals

Literals of type datetime have the syntax datetime(value), where a number of formats are supported for value, as indicated by the following table:

Example Value
datetime(2015-12-31 23:59:59.9)
Times are always in UTC. Omitting the date gives a time today.
datetime(null) See null values.
now() The current time.
now(-timespan) now()-timespan
ago(timespan) now()-timespan

now() and ago() indicate a datetime value compared with the moment in time when Kusto started to execute the query. These can appear multiple times in the same query, and a single value will be used for them all. (In other words, expressions such as now(-x) - ago(x) always evaluate to a timespan value of zero.)

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