Date/Time functions

Devart ODBC Driver for PostgreSQL supports the following date/time operators and functions for working with dates, times, timestamps, and intervals.
They cover arithmetic, binning, extraction, truncation, and construction of date/time values, including time zone–aware operations.

Date/time operators

Operator	Return type	Description
`date + integer`	`date`	Adds a number of days to a date.
`date + interval`	`timestamp`	Adds an interval to a date and returns a timestamp.
`date + time`	`timestamp`	Adds a time value to a date and returns a timestamp.
`interval + interval`	`interval`	Adds two intervals.
`timestamp + interval`	`timestamp`	Adds an interval to a timestamp.
`time + interval`	`time`	Adds an interval to a time value.
`- interval`	`interval`	Negates an interval (changes its sign).
`date - date`	`integer`	Subtracts two dates, returning the number of days between them.
`date - integer`	`date`	Subtracts a number of days from a date.
`date - interval`	`timestamp`	Subtracts an interval from a date and returns a timestamp.
`time - time`	`interval`	Subtracts two times-of-day, returning the interval between them.
`time - interval`	`time`	Subtracts an interval from a time value.
`timestamp - interval`	`timestamp`	Subtracts an interval from a timestamp.
`interval - interval`	`interval`	Subtracts one interval from another.
`timestamp - timestamp`	`interval`	Subtracts two timestamps, returning the interval between them.
`interval * double precision`	`interval`	Multiplies an interval by a scalar value.
`interval / double precision`	`interval`	Divides an interval by a scalar value.

Date/time functions

Function	Return type	Description
`age(timestamp, timestamp)`	`interval`	Subtracts two timestamps, returning a symbolic interval expressed in years, months, and days.
`age(timestamp)`	`interval`	Subtracts the given timestamp from the current date (at midnight), returning a symbolic interval.
`clock_timestamp()`	`timestamptz`	Returns the current date and time; the value continues to change during statement execution.
`current_date`	`date`	Returns the current date (without a time component).
`current_time([integer])`	`timetz`	Returns the current time of day with time zone, optionally with limited fractional second precision.
`current_timestamp([integer])`	`timestamptz`	Returns the current date and time with time zone, fixed at the start of the current transaction, optionally with limited precision.
`date_add(timestamptz, interval, [text])`	`timestamptz`	Adds an interval to a timestamp with time zone, handling Daylight Saving Time (DST) according to the optional time zone name.
`date_bin(interval, timestamp, timestamp)`	`timestamp`	Bins (rounds down) a timestamp into intervals of the given size, aligned to the specified origin timestamp.
`date_part(text, timestamp/interval)`	`double precision`	Returns the specified field (for example, hour, month, or day of week) from a timestamp or interval (equivalent to `extract`).
`date_subtract(timestamptz, interval, [text])`	`timestamptz`	Subtracts an interval from a timestamp with time zone, handling DST according to the optional time zone name.
`date_trunc(text, timestamp/interval, [text])`	same as input type	Truncates a date, timestamp, or interval to the specified precision (for example, hour, day); for `timestamptz`, an optional time zone name can be specified.
`extract(field from timestamp/interval)`	`numeric`	Returns a specified field (such as year, month, day, hour) from a timestamp or interval.
`isfinite(date/timestamp/interval)`	`boolean`	Returns `true` if the value is finite (not `+infinity` or `-infinity`).
`justify_days(interval)`	`interval`	Normalizes an interval by converting 30-day periods into whole months.
`justify_hours(interval)`	`interval`	Normalizes an interval by converting 24-hour periods into whole days.
`justify_interval(interval)`	`interval`	Applies both `justify_days` and `justify_hours`, and adjusts signs to produce a normalized interval.
`localtime([integer])`	`time`	Returns the current time of day without time zone, optionally with limited fractional second precision.
`localtimestamp([integer])`	`timestamp`	Returns the current date and time without time zone, fixed at the start of the current transaction.
`make_date(year, month, day)`	`date`	Constructs a date from integer year, month, and day components.
`make_interval(...)`	`interval`	Constructs an interval from individual components such as years, months, days, hours, minutes, and seconds.
`make_time(hour, min, sec)`	`time`	Constructs a time value from hour, minute, and second components.
`make_timestamp(...)`	`timestamp`	Constructs a timestamp (without time zone) from date and time components.
`make_timestamptz(..., [timezone])`	`timestamptz`	Constructs a timestamp with time zone from date and time components and an optional time zone name.
`now()`	`timestamptz`	Returns the current date and time with time zone, fixed at the start of the current transaction (same as `transaction_timestamp`).
`statement_timestamp()`	`timestamptz`	Returns the current date and time with time zone, fixed at the start of the current statement.
`timeofday()`	`text`	Returns the current date and time as a text string, similar to `clock_timestamp()`.
`transaction_timestamp()`	`timestamptz`	Returns the current date and time with time zone, fixed at the start of the current transaction.
`to_timestamp(double precision)`	`timestamptz`	Converts a Unix epoch value (seconds since `1970-01-01 00:00:00+00`) to a timestamp with time zone.