Idiom for something like vantage point / perspective, but for point in time rather than place

Solution 1:

Have you tried "in hindsight" or "in foresight"? They refer to a new understanding of a situation or a problem when viewed at another time.

From Merriam-Webster:

hindsight 
: the knowledge and understanding that you have about an
event only after it has happened
:  perception of the nature of an event after it has happened

foresight
:  the ability to see what will or might happen in the future
:  an act or the power of foreseeing :  prescience
:  provident care :  prudence <had the foresight to invest his money wisely>
:  an act of looking forward; also :  a view forward