It is time to remind ourselves of our dependence on one of the most obvious commodities we get from forest.
It is time to realize that the care of our forests is the immediate concern of every citizen.
Children, it is time for you to stop playing.
The boy is 7 years old. Why didn’t you send him to school? It is time for him to go to school.
Notice that in this pattern we can use an Infinitive after 'it’s time.'
It is time + Subject + Past Verb.
, it is (high) time you left the club.
Note there is no difference in meaning between.
It is time for us to leave.
It is time we left.
The past tense here does not have a past meaning. The past tense here is used to talk about something in Present.
English is certainly a funny language and not all grammatical rules can be explained like the above. One can argue about the use of Past tense but conventionally you have been using the construction in this way. Note, here in expression it is time… the past tense is used and not in all constructions this kind of deviation is possible.