In this article, I will give an example of specifying custom intervals for items in Zabbix so that they are polled only at the specified time, and not constantly at the usual interval.
Once I needed to monitor ONU signal levels on GPON OLT and EPON OLT, for this I created a template and configured low-level discovery in it, which allowed me to automatically discover new interfaces (ONU) and automatically create items, triggers and graphics for them.
See my article:
Configuring low-level discovery in Zabbix
But since the number of ONUs was very many thousands, polling via SNMP made serious loads for OLT devices. At first, I indicated the usual interval of 1 day (1d), but when the operators worked with devices, and at that moment Zabbix started polling via SNMP, this slowed down the work very much, even made it almost impossible, the devices responded very slowly to commands, because Zabbix created a load on the CPU devices. Therefore, I left the update interval 1d, but changed its type from “Flexible” to “Scheduled”, in which I specified wd1-7h1. Which means every day of the week 1-7 and 1 AM, i.e. Zabbix will perform an SNMP poll every day only at 1 am.
Here are some more examples:
1-7.01:00-4:00 (every night from 1:00 to 4:00)
1-5.08:00-17:00 (on weekdays during business hours)
For example, if you specify in the interval 5m, then the item will be polled every 5 minutes during the specified working hours.
See also official Zabbix documentation