Some additional repos to consider:
g4code/cron — G4 Cron like parser with ability to parse expressions with resolution in seconds - based on PHP Cron Expression Parser
natural-cron-expression — A parser that converts natural language to a cron expression
cronDate — A simple PHP class to get a cron expression from date string
Once a week...... I send out a list of most interesting PHP libraries and apps.
Want to get it?