Which cron dialect is this?

Five fields: minute, hour, day of month, month, day of week. It also accepts the common @daily style names. It does not accept a seconds field.

Why is the default timezone Johannesburg?

SuperStack is in South Africa, and a lot of jobs are written as if the server were on UTC. The default makes the local time obvious.

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Cron expression explainer

Enter a five-field cron expression. We describe it and list the next run times. The default timezone is Africa/Johannesburg (SAST).

Five fields, or a name such as @daily. SAST means Africa/Johannesburg. The expression is not stored.

How to use it

Enter five fields, or a name such as @daily.
Leave the timezone as Africa/Johannesburg unless the job really runs somewhere else. SAST is accepted as a name.
Read the next run times before you put the expression on a server. Monday morning in UTC is not Monday morning in Johannesburg.

Questions

Which cron dialect is this?: Five fields: minute, hour, day of month, month, day of week. It also accepts the common @daily style names. It does not accept a seconds field.
Why is the default timezone Johannesburg?: SuperStack is in South Africa, and a lot of jobs are written as if the server were on UTC. The default makes the local time obvious.
Is the expression stored?: No.

An automated client can POST JSON to /api/tools/cron with expression. The OpenAPI document is at /api/tools, with a short guide at /llms.txt. Nothing submitted is stored.