4 ms·

This is incredible. While there is still a decent rate of false-positives or errors, it's such a nicer user interface than the powerful yet hard-to-read cron sy

This is incredible. While there is still a decent rate of false-positives or errors, it's such a nicer user interface than the powerful yet hard-to-read cron syntax. Any chance it could be made into a library/api?

jacobpedd 4y ago
A very good chance actually! Stay tuned
- coding123 4y ago
  Yes, this would be a pretty amazing for biz people to type "every other day" or something and have the backend know what that means.
TylerE 4y ago
My favorite cron “feature” is that the day of week field operates acts as an “or” and not an “and”. This will come as an unpleasant surprise when you try to schedule something to run on, say, the first Friday of the month. There are workarounds, mostly involving backticked date invocations, but they’re hard to both write and read.
- jbotz 4y ago
  Are you sure? The man page for Vixie cron at least doesn't imply that and it's not what I remember, and the web page this links to also doesn't think that's true. So "First Friday of the month at midnight" gives "0 0 1-7 * 5".
  - TylerE 4y ago
    From man 5 crontab Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't ), the command will be run when either field matches the current time. For example, ``30 4 1,15 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.
  - Izkata 4y ago
    Aside from the manpage, you can also check ones you're unsure of on crontab.guru - https://crontab.guru/#0_0_1-7_*_5 https://crontab.guru/#0_0_1-7_*_5
- cuu508 4y ago
  In Debian cron, you can do: 0 0 */50,1-7 * FRI It works, but it's a bit of a hack (to put it mildly ;-) ) Consider this expression: 0 0 1-7 * FRI This one will run on dates 1-7, and additionally on every Friday. This is almost what we want, except we want an "AND" relationship between the day-of-month and the day-of-week fields, instead of the "OR" relationship. The weird extra */50 bit exploits a quirk in Debian cron's expression parsing logic. It fools cron into thinking the day-of-month field is a wildcard field, and into applying the "AND" logic.

jacobpedd 4y ago

A very good chance actually! Stay tuned

coding123 4y ago
Yes, this would be a pretty amazing for biz people to type "every other day" or something and have the backend know what that means.

TylerE 4y ago

My favorite cron “feature” is that the day of week field operates acts as an “or” and not an “and”. This will come as an unpleasant surprise when you try to schedule something to run on, say, the first Friday of the month. There are workarounds, mostly involving backticked date invocations, but they’re hard to both write and read.

jbotz 4y ago
Are you sure? The man page for Vixie cron at least doesn't imply that and it's not what I remember, and the web page this links to also doesn't think that's true. So "First Friday of the month at midnight" gives "0 0 1-7 * 5".
- TylerE 4y ago
  From man 5 crontab Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't ), the command will be run when either field matches the current time. For example, ``30 4 1,15 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.
- Izkata 4y ago
  Aside from the manpage, you can also check ones you're unsure of on crontab.guru - https://crontab.guru/#0_0_1-7_*_5 https://crontab.guru/#0_0_1-7_*_5
cuu508 4y ago
In Debian cron, you can do: 0 0 */50,1-7 * FRI It works, but it's a bit of a hack (to put it mildly ;-) ) Consider this expression: 0 0 1-7 * FRI This one will run on dates 1-7, and additionally on every Friday. This is almost what we want, except we want an "AND" relationship between the day-of-month and the day-of-week fields, instead of the "OR" relationship. The weird extra */50 bit exploits a quirk in Debian cron's expression parsing logic. It fools cron into thinking the day-of-month field is a wildcard field, and into applying the "AND" logic.