Hmm, interesting question. Even if the processing will be super-fast, we still have a chance of slow comunications, slow-downs on agent side, etc.

I think that the best solution would be expanding of the function to support second parameter which would specify how many last values we compare with ZABBIX server's system time. Like:

fuzzytime(5, 3) - if all 3 most recent values are within 5 seconds range, return 0

Will it help?

http://www.zabbix.com/forum/showthread.php?p=27268