I need detail on how the reader know two months has passed in act 1 to act !!

It says on line one thirty eight ” but two months dead, nay, not so much, not two,” which means the king died two months ago. He also talks about his mothers remarriage which took about a month later in lines 151-153-” Would have mourned longer-married with my uncle, My fathers brother, but no more like my father Than I to Hercules. Within a month,”.

I have to go with a total of three months here.