The default pattern (MM/dd/yyyy) returns the date in month/day/year format. So, for example, the date might return as 06/15/2006 if the function _now() is entered with no pattern.

Pattern characters can be assembled to provide the desired return. The following table lists the characters and the expected result. Characters are case-sensitive. All examples are based on a time of June 15, 2006 at 13:02:08 PM.

Except for special pattern characters, such as u, the function call must provide sufficient pattern characters to fill the field for those where length is specified. The following table provides a few examples:

Note: Special characters can be included in the pattern by using an apostrophe. To avoid compiler confusion, surround the pattern string using double quotes.

The pattern Un represents the best time available for the system at the nanosecond level. This method can only be used to measure elapsed time and is not related to any other notion of system or wall-clock time. The value returned represents nanoseconds since some fixed but arbitrary. This method provides nanosecond precision, but not necessarily nanosecond accuracy. No guarantees are made about how frequently values change.

For example:

_ftstamp() yields 2006-07-21T19:42:44:609Z

The special pattern of the word compress eliminates the separator characters, yielding 20060721194244609Z. The compress option simplifies using the output in file names and in other situations in which the separator characters would be inappropriate.

For example:

_fmtdate('yyyy.MM.dd', _dateof('MM/dd/yyyy','06/25/2009')) yields the following:

 2009.06.25

It is sometimes desirable to obtain the date for some moment in relation to the current moment. For example, you may want the current date/time for a date one week in the past:

_fmtdate('yyyy/MM/dd hh:mm:ss',_imul(_isub(_now(u),_imul(86400,7)),1000))

Replace the 7 in this example with the number of days desired. 86400 is the number of seconds in a day.

For example:

_dateof('MM/dd/yyyy', '06/25/2009') yields the following:

 1245902400000

To create a duration suitable for date arithmetic, use the Zulu zone. This avoids any offset, so that a pattern, such as ss will give absolute seconds.

Note: The _iadd() and _isub() functions are preferred for date arithmetic because they operate on long integers with more precision than _add() and _sub().

Compute and display the time ten minutes ago. This example was run at 09/08/27 05:13:54.

_fmtdate('yy/MM/dd hh:mm:ss',_isub(_now(U),_dateof('mm',10,gmt)))

Results in 09/08/27 05:03:54.