Preposition of Time: In our life time is more important. Therefore we must write sentences of time using correct preposition.
See these examples first:
* I was born in February month.
* I was born in 1972.
* I was born in the year 2012.
* I was born in 2nd week of September. 
* I was born in early morning.
* I will be there in five minutes.

Prepositions- IN, ON , AT – see this vedio,

READ :  Pronoun Kinds of Pronoun | Class 6 Part 1