Sah::Schema::date::tz_offset - Timezone offset in seconds from UTC (only known offsets are allowd, coercible from string), e.g. 25200 or "+07:00"


This document describes version 0.018 of Sah::Schema::date::tz_offset (from Perl distribution Sah-Schemas-Date), released on 2022-10-12.


Sample data and validation results against this schema

 ""  # INVALID

 "UTC"  # valid, becomes 0

 3600  # valid, becomes 3600

 -43200  # valid, becomes -43200

 -12  # valid, becomes -43200

 -1200  # valid, becomes -43200

 "-12:00"  # valid, becomes -43200

 "UTC-12"  # valid, becomes -43200

 "UTC-1200"  # valid, becomes -43200

 "UTC+12:45"  # valid, becomes 45900

 "UTC-13"  # INVALID

 "UTC+12:01"  # INVALID (Unknown offset)

Using with Data::Sah

To check data against this schema (requires Data::Sah):

 use Data::Sah qw(gen_validator);
 my $validator = gen_validator("date::tz_offset*");
 say $validator->($data) ? "valid" : "INVALID!";

The above schema returns a boolean result (true if data is valid, false if otherwise). To return an error message string instead (empty string if data is valid, a non-empty error message otherwise):

 my $validator = gen_validator("date::tz_offset", {return_type=>'str_errmsg'});
 my $errmsg = $validator->($data);
 # a sample valid data
 $data = 3600;
 my $errmsg = $validator->($data); # => ""
 # a sample invalid data
 $data = "UTC-13";
 my $errmsg = $validator->($data); # => "Must be one of [-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400,-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400,-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400]"

Often a schema has coercion rule or default value, so after validation the validated value is different. To return the validated (set-as-default, coerced, prefiltered) value:

 my $validator = gen_validator("date::tz_offset", {return_type=>'str_errmsg+val'});
 my $res = $validator->($data); # [$errmsg, $validated_val]
 # a sample valid data
 $data = 3600;
 my $res = $validator->($data); # => ["",3600]
 # a sample invalid data
 $data = "UTC-13";
 my $res = $validator->($data); # => ["Must be one of [-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400,-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400,-43200,-39600,-37800,-36000,-34200,-32400,-30600,-28800,-25200,-21600,-18000,-16200,-14400,-12600,-10800,-9000,-7200,-3600,-2640,-1521,0,0,1200,1800,3600,5040,5400,7200,9000,10800,12600,14400,16200,17460,18000,19800,20400,20700,21600,23400,25200,26400,27000,28800,30600,31500,32400,34200,35100,36000,37800,39600,41400,43200,45900,46800,49500,50400]",-46800]

Data::Sah can also create validator that returns a hash of detailed error message. Data::Sah can even create validator that targets other language, like JavaScript, from the same schema. Other things Data::Sah can do: show source code for validator, generate a validator code with debug comments and/or log statements, generate human text from schema. See its documentation for more details.

Using with Params::Sah

To validate function parameters against this schema (requires Params::Sah):

 use Params::Sah qw(gen_validator);

 sub myfunc {
     my @args = @_;
     state $validator = gen_validator("date::tz_offset*");

Using with Perinci::CmdLine::Lite

To specify schema in Rinci function metadata and use the metadata with Perinci::CmdLine (Perinci::CmdLine::Lite) to create a CLI:

 # in lib/
 our %SPEC;
 $SPEC{myfunc} = {
     v => 1.1,
     summary => 'Routine to do blah ...',
     args => {
         arg1 => {
             summary => 'The blah blah argument',
             schema => ['date::tz_offset*'],
 sub myfunc {
     my %args = @_;

 # in
 use Perinci::CmdLine::Any;

 # in command-line
 % ./ --help
 myapp - Routine to do blah ...

 % ./ --version

 % ./ --arg1 ...

Using with Type::Tiny

To create a type constraint and type library from a schema:

 package My::Types {
     use Type::Library -base;
     use Type::FromSah qw( sah2type );

         sah2type('$sch_name*', name=>'DateTzOffset')

 use My::Types qw(DateTzOffset);


Only timezone offsets that are known to exist are allowed. For example, 1 second (+00:00:01) is not allowed. See date::tz_offset_lax for a more relaxed validation.

A coercion from these form of string is provided:

 UTC-14 or UTC+12 or UTC+12:45 or UTC-00:25:21
 -14 or +12, -1400 or +12:00

A coercion from timezone name is also provided.


Please visit the project's homepage at


Source repository is at


perlancar <>


To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

 % prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.


This software is copyright (c) 2022, 2020, 2019 by perlancar <>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.


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