An expression like 15 2 * * 1-5 is easy to misread, and the cost of being wrong is a job that runs at the wrong time or far more often than intended.
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Cron Expression Parser
Expression
Free · API · MCPToolYour platform
Use Cron Expression Parser three ways
The free Cron Expression Parser on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse Cron Expression Parser here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is Cron Expression Parser?
An expression like 15 2 * * 1-5 is easy to misread, and the cost of being wrong is a job that runs at the wrong time or far more often than intended. This cron expression parser takes any five-field expression and returns the next eight times it will fire in UTC — concrete timestamps rather than a prose description, which is what actually settles the question.
Eight runs is usually enough to see the pattern, including whether an intended weekly job is really daily or whether a wildcard slipped into the minute field. Invalid expressions fail with the parser's error instead of a guess. Times are UTC, so a scheduler configured in a local zone needs conversion, and platform extensions such as Quartz seconds or AWS day-of-week numbering are outside this format. When you need to build a schedule rather than inspect one, Cron Expression Generator assembles the fields for you.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/cron-expression-parser and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about Cron Expression Parser?
How many upcoming runs are shown?
Eight, which is normally enough to see whether the pattern is hourly, daily, weekly, or accidentally something else entirely.
Does it explain the expression in words?
It returns concrete UTC timestamps rather than prose. Real times are harder to misread than a sentence describing them.
What if the expression is invalid?
You get the parser error naming the problem, so a typo in a field is caught before it reaches a scheduler.
What are the key features of Cron Expression Parser?
Eight concrete run times
Enough upcoming timestamps to recognise the real cadence at a glance.
UTC output
One unambiguous reference zone, which is also what most container schedulers use.
Clear parse errors
Malformed expressions are rejected with a message rather than silently accepted.
How do you use Cron Expression Parser?
Paste the expression
Five space-separated fields from a crontab, manifest, or workflow file.
Read the next runs
Check the cadence and the times against what the job is supposed to do.
Correct if needed
Rebuild the schedule with the generator when the preview disagrees with your intent.
Auditing schedules you inherited
Reviewing an existing set of cron entries is a good use of ten minutes, and three questions cover most of the value. Does each expression match its comment or job name — a job called nightly-cleanup running every fifteen minutes is a real and common finding. Do heavy jobs collide — several expressions firing at midnight on the first of the month can create a load spike nobody planned. Is anything running far more often than intended — usually a wildcard in the minute field.
Pasting each expression here and reading the actual timestamps answers all three faster than reasoning about the syntax.
Reading times in the right zone
Next runs are reported in UTC because it is unambiguous. If your scheduler is configured for a local zone, convert the output with Timestamp Converter before concluding the schedule is right — an hour's difference is easy to miss and daylight-saving shifts it twice a year.
When the preview shows the schedule is wrong, Cron Expression Generator is the faster way to build a corrected one, since specifying fields by name avoids the position-counting mistakes that caused the problem originally.
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