The next ten runs
Build one
Read and worked out in this browser — nothing is uploaded and nothing is stored. This parses Vixie cron, the five-field syntax Linux and macOS use. Quartz and Spring, which most Java tutorials are written in, take six or seven fields and count Sunday as 1 rather than 0 — an expression moved between the two does not fail loudly, it quietly means something else, so those are recognised and named. Remember that when the day-of-month and the day-of-week are both set, cron runs the job when either matches, not both.
The Cron Expression Parser needs JavaScript: the expression is parsed and the run times are computed in this browser, which is why nothing you paste has to be sent anywhere. With JavaScript switched off there is nothing to do the work.