The time at which any individual of any age or gender (especially those under the legal drinking age) gets shitty-wasted and Hammered.
Shmammer time can be throughout any time of the day, especially in the extremely early hours of the morning (for minors= "late" hours of the night) and with anyone who is willing and capable of getting shmammered as well.
Warning: not suggested to get shmammered alone or if unintentionally knocked up.
Lindsay- "Dude, It's Shmammer time."
drinks a whole bottle of wine in 10 minutes by herself
Eric-" Lindsay you're shmammered."
Lindsay- "I know but I let the dogs out 20 minutes ago and I didn't now you were getting me chicken strips again!"