Come for the t-shirts, stay for the learning!
Do you know about the Omer? It's the 49-day period between Passover and Shavuot, and it commemorates Moses's proclamation to the ancient Israelites that God would give them the Torah 49 days after the exodus from Egypt.
The Israelites counted down the days, refusing to celebrate their liberation until they'd received the Torah -- after all, they weren't truly free yet, since they hadn't received the word of God.
In tribute, we do the same.
(Kids, it's kinda like how you're counting down the days from now until summer break. Except instead of a drunk weekend at the beach, you get the Torah.)
By tradition, we're not supposed to have parties or weddings during this time, and many men abstain from shaving or cutting their hair.
At some point, somebody decided to exempt the 33rd day from this prohibition. On that day, called "Lag," you can party all you want, get married to your heart's content, and pay your ol' barber a long-overdue visit.
(Kids, this would be a good time to go to the beach! Wear our Israeli Flag Tank Top.)
Enjoy your Lag, everybody! We'll be kicking back with some burgers and a good LAG-ER. Yuengling, perhaps?