There is wrong description of fuzzytime function in Russian tranlsation (https://www.zabbix.com/documentation/4.0/ru/manual/appendix/triggers/functions)

In contrast of english version in russian there is written fuzzytime returns 0 if difference between item value and Zabbix server timestamp is less than or equal to T seconds

It's written right in russian documentation for zabbix2.0, all other versions are incorrect.