DSQL, PSQL

Changed in

2.5

Syntax

Result type

BIGINT

Description

Returns the number of years, months, weeks, days, hours, minutes, seconds or milliseconds elapsed between two date/time values. (The unit is new in 2.5.)

• DATE and TIMESTAMP arguments can be combined. No other mixes are allowed.

• With TIMESTAMP and DATE arguments, all units can be used. (Prior to Firebird 2.5, units smaller than DAY were disallowed for DATEs.)

• With TIME arguments, only HOUR, MINUTE, and MILLISECOND can be used.

• It does, however, look at all the bigger units. So:

• A negative result value indicates that moment2 lies before moment1.

Examples

datediff (hour from current_timestamp to timestamp '12-Jun-2059 06:00')
datediff (minute from time '0:00' to current_time)
datediff (day from current_date to cast(? as date))

See also

, Operations Using Date and Time Values