CronLens
Cron expressions are easy to write and easy to get wrong. CronLens is a developer-focused cron visualizer: paste a cron string and instantly see a plain-English translation, the next run times (timezone- and DST-aware), a field-by-field breakdown, and warnings for expressions that are valid but surprising. Supports 5-field, 6-field and Quartz dialects — everything runs client-side, nothing leaves your browser.