PostgreSQL Date & Time Function
A list of all important Date and Time related functions:
| Function |
Description |
| AGE() |
Subtract arguments |
| CURRENT DATE/TIME() |
It specifies current date and time. |
| DATE_PART() |
Get subfield (equivalent to extract) |
| EXTRACT() |
Get subfield. |
| ISFINITE() |
Test for finite date ,time and interval (not +/-infinity) |
| JUSTIFY |
Adjust interval |
AGE(timestamp, timestamp) & AGE(timestamp):

| function |
description |
| age(timestamp, timestamp) |
when invoked with the timestamp form of the second argument, age() subtract arguments, producing a "symbolic" result that uses years and months and is of type interval. |
| age(timestamp) |
when invoked with only the timestamp as argument, age() subtracts from the current_date (at midnight). |
Let's take an example to check the AGE(timestamp, timestamp) query.
See this example:
Open query page by pressing Ctrl+E.
Execute this query:
SELECT AGE(timestamp '2016-01-26', timestamp '1947-08-15');
Example for function AGE(timestamp) is:

It is used to produce the current age.
Execute the following query:
SELECT AGE(timestamp '1947-08-15');
Current DATE/TIME()

Following is a list of functions that return values related to the current date and time.
| Function |
Description |
| CURRENT_DATE |
Delivers current date. |
| CURRENT_TIME |
Delivers values with time zone. |
| CURRENT_TIMESTAMP |
Delivers values with time zone. |
| CURRENT_TIME(precision) |
Optionally takes a precision parameter, which causes the result to be rounded to that many fractional digits in the seconds field. |
| CURRENT_TIMESTAMP(precision) |
Optionally takes a precision parameter, which causes the result to be rounded to that many fractional digits in the seconds field. |
| LOCALTIME |
Delivers values without time zone. |
| LOCALTIMESTAMP |
Delivers values without time zone. |
| LOCALTIME(precision) |
Optionally takes a precision parameter, which causes the result to be rounded to that many fractional digits in the seconds field. |
| LOCALTIMESTAMP(precision) |
Optionally takes a precision parameter, which causes the result to be rounded to that many fractional digits in the seconds field. |
Now, you can check the following commands:
For current time:
SELECT CURRENT_TIME;
For current date:
SELECT CURRENT_DATE;
For current timestamp (date and time both)
SELECT CURRENT_TIMESTAMP;
Current timestamp with more precision:
SELECT CURRENT_TIMESTAMP(2);
Local Timestamp:
SELECT LOCALTIMESTAMP;
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