cron_clock

A cron expression parser. Works with stable Rust v1.28.0. The project is based on zslayton/cron, thank him very much.

In addition to the regular expressions, you can also use the following shortcut expressions with Schedule::from_str, such as @yearly @monthly @weekly @daily @hourly @minutely @secondly, make cron- Expression Iterator.

Tips

If you need a periodicized task manager, you may need delay-timer (Time-manager of delayed tasks. Like crontab, but synchronous asynchronous tasks are possible, and dynamic add/cancel/remove is supported) .

Example

extern crate cron;
extern crate chrono;

use cron::Schedule;
use chrono::Utc;
use std::str::FromStr;

fn main() {
  //               sec  min   hour   day of month   month   day of week   year
  let expression = "0   30   9,12,15     1,15       May-Aug  Mon,Wed,Fri  2018/2";
  let schedule = Schedule::from_str(expression).unwrap();
  println!("Upcoming fire times:");
  for datetime in schedule.upcoming(Utc).take(10) {
    println!("-> {}", datetime);
  }
}

/*
Upcoming fire times:
-> 2018-06-01 09:30:00 UTC
-> 2018-06-01 12:30:00 UTC
-> 2018-06-01 15:30:00 UTC
-> 2018-06-15 09:30:00 UTC
-> 2018-06-15 12:30:00 UTC
-> 2018-06-15 15:30:00 UTC
-> 2018-08-01 09:30:00 UTC
-> 2018-08-01 12:30:00 UTC
-> 2018-08-01 15:30:00 UTC
-> 2018-08-15 09:30:00 UTC
*/

Example shortcut expressions & ScheduleIteratorOwned

 extern crate chrono;
 extern crate cron_clock;

 use cron_clock::Schedule;
 use chrono::Utc;
 use std::str::FromStr;

 fn main() {
   // shortcut expressions
   let expression = "@hourly";
   let schedule = Schedule::from_str(expression).unwrap();
   println!("Upcoming fire times:");
   // `upcoming_owned` Get iterators with ownership, so you don't have lifetime to worry about.
   for datetime in schedule.upcoming_owned(Utc).take(10) {
     println!("-> {}", datetime);
   }
 }