---
name: "Test::MockTime"
section: "3pm"
platform: "linux"
package: "perl-test-mocktime"
version: "0.17-11"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Test::MockTime"
---

# Test::MockTime(3pm)

Replaces actual time with simulated time

## NAME

Test::MockTime - Replaces actual time with simulated time

## VERSION

Version 0.17

## SYNOPSIS

```
  use Test::MockTime qw( :all );
  set_relative_time(-600);
  # do some tests depending on time increasing from 600 seconds ago
  set_absolute_time(0);
  # do some more tests depending on time starting from the epoch
  # epoch may vary according to platform.  see perlport.
  set_fixed_time(CORE::time());
  # do some more tests depending on time staying at the current actual time
  set_absolute_time('1970-01-01T00:00:00Z');
  # do some tests depending on time starting at Unix epoch time
  set_fixed_time('01/01/1970 00:00:00', '%m/%d/%Y %H:%M:%S');
  # do some tests depending on time staying at the Unix epoch time
  restore_time();
  # resume normal service
```

## DESCRIPTION

This module was created to enable test suites to test code at specific  points in time. Specifically it overrides localtime, gmtime and time at compile time and then relies on the user supplying a mock time via  set\_relative\_time, set\_absolute\_time or set\_fixed\_time to alter future  calls to gmtime,time or localtime.

## SUBROUTINES/METHODS

- set\_absolute\_time

  If given a single, numeric argument, the argument is an absolute time (for example, if 0 is supplied, the absolute time will be the epoch), and calculates the offset to allow subsequent calls to time, gmtime and localtime to reflect this.

  for example, in the following code

  ```
    Test::MockTime::set_absolute_time(0);
    my ($start) = time;
    sleep 2;
    my ($end) = time;
  ```

  The `$end` variable should contain 2 seconds past the epoch;

  If given two arguments, the first argument is taken to be an absolute time in some string format (for example, "01/01/1970 00:00:00").  The second argument is taken to be a `"strptime"` format string (for example, "%m/%d/%Y `%H:`%M:%S"). If a single argument is given, but that argument is not numeric, a `"strptime"` format string of "%Y-%m-%dT%H:%M:%SZ" is assumed.

  for example, in the following code

  ```
    Test::MockTime::set_absolute_time('1970-01-01T00:00:00Z');
    my ($start) = time;
    sleep 2;
    my ($end) = time;
  ```

  The `$end` variable should contain 2 seconds past the Unix epoch;

- set\_relative\_time($relative)

  takes as an argument an relative value from current time (for example, if -10 is supplied, current time be converted to actual machine time - 10 seconds) and calculates the offset to allow subsequent calls to time,gmtime and localtime to reflect this.

  for example, in the following code

  ```
    my ($start) = time;
    Test::MockTime::set_relative_time(-600);
    sleep 600;
    my ($end) = time;
  ```

  The `$end` variable should contain either the same or very similar values to the `$start` variable.

- set\_fixed\_time

  If given a single, numeric argument, the argument is an absolute time (for example, if 0 is supplied, the absolute time will be the epoch).  All subsequent calls to gmtime, localtime and time will return this value.

  for example, in the following code

  ```
    Test::MockTime::set_fixed_time(time)
    my ($start) = time;
    sleep 3;
    my ($end) = time;
  ```

  the `$end` variable and the `$start` variable will contain the same results

  If given two arguments, the first argument is taken to be an absolute time in some string format (for example, "01/01/1970 00:00:00").  The second argument is taken to be a `"strptime"` format string (for example, "%m/%d/%Y `%H:`%M:%S"). If a single argument is given, but that argument is not numeric, a `"strptime"` format string of "%Y-%m-%dT%H:%M:%SZ" is assumed.

- **restore()**

  restore the default time handling values.  `"restore_time"` is an alias. When exported with the 'all' tag, this subroutine is exported as `"restore_time"`.

## CONFIGURATION AND ENVIRONMENT

Test::MockTime requires no configuration files or environment variables.

## DEPENDENCIES

Test::MockTime depends on the following non-core Perl modules.

- •

  Time::Piece 1.08 or greater

## INCOMPATIBILITIES

None reported

## BUGS AND LIMITATIONS

Probably.

## AUTHOR

David Dick \<ddick@cpan.org\>

## LICENSE AND COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

## ACKNOWLEDGEMENTS

Thanks to a use.perl.org journal entry \<http://use.perl.org/~geoff/journal/20660\> by  Geoffrey Young.