How long is long enough?

When it comes to monitoring changes
How long do you guys give in Google SERPs?

For example,
you tweak a page for keywords and wait to see whether ot works or not in the results

do you wait a week / month / 90 days
before you conclude it worked or didnt work?

Thanks again

 

That is quality of your worth.

 

I think is daily, I can see changes happened everyday

 

I am monitoring the keywords i am working on daily and continue working on them. If i don't see any result after some days or weeks (depents on the search volume) drop it sometimes and continue focussing on others.