Here are a few:foreverawhilemany yearseternityeverlasting
Yesteryear, maybe?
instead of long period of time, you can use phrases like:a long terma long spella phaseyou can even use the word tenure if it suits the situation.
'thou' In modern English ,the 2nd. . person is 'you' In historical/romantic English, the 2nd. person is 'thou'.
Dwelt- to get a hold of something for a long time. or you have hanged around that thing for a long period of time Don't now the other word for dwelt(sorry!)
If Time : Duration If distance: Size/Length/Height as applicable.
another word for no time to play is buisy
Truly
no other word really...
REALLY long
Another word for long is "lengthy" or "extended."
Analyze, monitor, keep track of