What does */5 * * * * mean?

It means every 5 minutes, of every hour, every day of the month, every month, on every day of the week, since the step value */5 in the minute field fires on minute 0, 5, 10 and so on.

What is the difference between Unix cron and Quartz cron?

Unix cron has 5 fields with no seconds; Quartz adds a leading seconds field and needs a ? in either day-of-month or day-of-week because Quartz cannot match both simultaneously, unlike Unix cron.

Can I convert a cron expression for Hangfire?

Yes, Hangfire uses the Cronos library, which accepts standard 5-field Unix cron and an optional 6-field form with leading seconds, so the conversion panel shows your expression largely unchanged with a note explaining that.

Why does the Next executions list say runs are unavailable?

The underlying parser used for next-run calculation does not accept every Quartz-specific token, such as ? or L, so a valid Quartz description can still leave the next-run list empty for that expression.

Cron Viewer

Explain cron expressions in plain English and preview upcoming run times locally.

Local, Runs entirely in your browser, your data never leaves your device.

Loading tool…

Read a cron expression without counting fields on your fingers

A cron expression like 30 8 * * 1-5 is quick to write and slow to read back, especially once ranges, steps and lists of days are involved. This tool parses the expression you type, describes its schedule in plain English, and lists the next six times it would fire from the current moment. It also converts a standard 5-field Unix expression toward Quartz and Hangfire syntax. Everything runs locally in your browser as you type.

How to use the Cron Viewer

Type a cron expression into the input, or pick one of the preset schedules below it.
Read the plain-English description of the schedule in the panel underneath the input.
Switch the Dialect selector between Unix and Quartz to match the field count you're working with.
Check the Next executions list on the right for the next six times the schedule would fire.
Copy the Quartz or Hangfire conversion if you need the same schedule in a different scheduler's syntax.

Unix cron uses 5 fields (minute, hour, day-of-month, month, day-of-week); Quartz uses 6 or 7 fields with a leading seconds field and requires a ? in whichever of day-of-month or day-of-week is unused. The two dialects also number Sunday differently in the day-of-week field.

Next-run calculation depends on the underlying parser accepting the expression; some Quartz-only syntax such as L or W in the day fields can produce a description without a usable next-run list.

Frequently asked questions

What does */5 * * * * mean?: It means every 5 minutes, of every hour, every day of the month, every month, on every day of the week, since the step value */5 in the minute field fires on minute 0, 5, 10 and so on.
What is the difference between Unix cron and Quartz cron?: Unix cron has 5 fields with no seconds; Quartz adds a leading seconds field and needs a ? in either day-of-month or day-of-week because Quartz cannot match both simultaneously, unlike Unix cron.
Can I convert a cron expression for Hangfire?: Yes, Hangfire uses the Cronos library, which accepts standard 5-field Unix cron and an optional 6-field form with leading seconds, so the conversion panel shows your expression largely unchanged with a note explaining that.
Why does the Next executions list say runs are unavailable?: The underlying parser used for next-run calculation does not accept every Quartz-specific token, such as ? or L, so a valid Quartz description can still leave the next-run list empty for that expression.