Janet 1.39.1-e9c6678 Documentation
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cron

Timer library for interfacing with the UNIX crontab format.

The cron format support is based on the unix cron syntax, with an optional seconds field. Each field can be a comma separated list of individual values or a range of values.

A range has three variants as follows:

1. Two values with a "-" between them, optionally followed by a "/" and a step value.
2. An asterisk ("*") followed by a "/" and a step value. This implies every "step" value.
3. A single value followed by a "/" and a step value. This implies every "step" value starting with the single value. I.e., 2/3 implies every 3 units from 2 to max units.

A single asterisk ("*") can be used to denote all possible values.

The fields:

• minutes: 0-5
• hours: 0-2
• day of month: 1-3
• month: 1-12. Also allowed are the following month codes in any case
jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec
• day of week: 0-7, where 0 or 7 is sunday, monday is 1, etc. allows the following day codes (any case)
sun,mon,tue,wed,thu,fri,sat
• seconds (optional): 0-5

Cron schedules are represented as tuples of 7 values, a string representation, followed by 6 bitmaps representing matching timestamps. Bitmaps are represented as any byte sequence.

[string-rep minutes hours day-of-month month day-of-week seconds]

Note that we have second precision here as opposed to minute precision.

Reference

cron/check cron/next-timestamp cron/parse-cron

(check cron &opt time local)

Check if a given time matches a cron specifier.

(next-timestamp cron &opt time local)

Given a cron schedule, get the next instance on the cron tab after time

(parse-cron str)

Parse a cron string into a valid cron schedule object