Schedules are used to automatically start your crawlers at certain times. Each schedule can be associated with a number of crawlers and it is also possible to override the settings of each of the crawlers in a similar fashion as when invoking the crawler using the API.
The schedules use cron expressions to specify the times of the run. The expression has the following structure:
|1||second||0 - 59||, - * /||yes|
|2||minute||0 - 59||, - * /||no|
|3||hour||0 - 23||, - * /||no|
|4||day of month||1 - 31||, - * /||no|
|5||month||1 - 12||, - * /||no|
|6||day of week||0 - 7 (0 or 7 is Sunday)||, - * /||no|
Note that all dates and times in the cron expression are always assumed to be in the UTC time zone. The minimum interval between runs is 10 seconds; if your next run is scheduled sooner than 10 seconds after the previous run, the next run will be skipped.
0 8 * * * every day at 8am
0 0 * * 0 every 7 days (at 00:00 on Sunday)
*/3 * * * * every 3rd minute
0 0 1 */2 * every other month (at 00:00 on the first day of month, every 2nd month)
Additionally, you can use the following shortcut expressions:
0 0 1 1 *)
0 0 1 * *)
0 0 * * 0)
0 0 * * *)
0 * * * *)
You can find more information and examples of cron expressions on crontab.guru.