cron parser
Library for parsing cron expressions with timezone support.
Example:
use chrono::{TimeZone, Utc};
use chrono_tz::Europe::Lisbon;
use cron_parser::parse;
fn main() {
if let Ok(next) = parse("*/5 * * * *", &Utc::now()) {
println!("when: {}", next);
}
// passing a custom timestamp
if let Ok(next) = parse("0 0 29 2 *", &Utc.timestamp(1893456000, 0)) {
println!("next leap year: {}", next);
assert_eq!(next.timestamp(), 1961625600);
}
assert!(parse("2-3,9,*/15,1-8,11,9,4,5 * * * *", &Utc::now()).is_ok());
assert!(parse("* * * * */Fri", &Utc::now()).is_err());
// use custom timezone
assert!(parse("*/5 * * * *", &Utc::now().with_timezone(&Lisbon)).is_ok());
}
Cron table:
# โโโโโโโโโโโโโโโโโโโโโโ minute (0 - 59)
# โ โโโโโโโโโโโโโโโโโโโโ hour (0 - 23)
# โ โ โโโโโโโโโโโโโโโโโโ dom (1 - 31) day of month
# โ โ โ โโโโโโโโโโโโโโโโ month (1 - 12)
# โ โ โ โ โโโโโโโโโโโโโโ dow (0 - 6 or Sun - Sat) day of week (Sunday to Saturday)
# โ โ โ โ โ
# โ โ โ โ โ
# โ โ โ โ โ
# * * * * * <command to execute>
| Field | Required | Allowed values | Allowed special characters |
|---|---|---|---|
| Minutes | Yes | 0โ59 | * , - / |
| Hours | Yes | 0โ23 | * , - / |
| Day of month | Yes | 1โ31 | * , - / |
| Month | Yes | 1โ12 | * , - / |
| Day of week | Yes | 0โ6 or Sun-Sat | * , - / |
For the day of the week, when using a Weekday (Sun-Sat) the expression
*/Dayis not supported instead use the integer, reasons for this is that for example*/Wed=*/3translates to run every 3rd day of week, this means Sunday, Wednesday, Saturday.
-
*any value -
,value list separator -
-range of values -
/step values
Depends on crate chrono.
Example of Cargo.toml:
[dependencies]
chrono = "^0.4"
cron-parser = "*"
Getting the next 10 leap year iterations:
use chrono::{DateTime, Utc};
use cron_parser::parse;
fn main() {
let now = Utc::now();
let mut crons = Vec::<DateTime<Utc>>::new();
let mut next = parse("0 0 29 2 *", &now).unwrap();
for _ in 0..10 {
next = parse("0 0 29 2 *", &next).unwrap();
crons.push(next);
}
for x in crons {
println!("{} - {}", x, x.timestamp());
}
}
It will print something like:
2024-02-29 00:00:00 UTC - 1709164800
2028-02-29 00:00:00 UTC - 1835395200
2032-02-29 00:00:00 UTC - 1961625600
2036-02-29 00:00:00 UTC - 2087856000
2040-02-29 00:00:00 UTC - 2214086400
2044-02-29 00:00:00 UTC - 2340316800
2048-02-29 00:00:00 UTC - 2466547200
2052-02-29 00:00:00 UTC - 2592777600
2056-02-29 00:00:00 UTC - 2719008000
2060-02-29 00:00:00 UTC - 2845238400
