A bouncer is likely to turn you away with a recently expired ID. The bar needs to establish that they're properly checking IDs for liability reasons, no one is catching every fake and no one actually cares if it's your valid real id and it happens to be expired. But bouncers are hired to be sticklers.

It's common to give expired IDs to younger friends as a fake, and people tend not to replace their fake IDs when they read as expired. So it's a red flag that an ID is likely fake. This is doubly true if you are just 21.

But there is practically no enforcement in Philadelphia, and in my experience ID checks are uncommon in places without bouncers. Unless you look very young, and order something obvious like a Long Island Ice Tea. Plenty of places won't even ask. If you have any other form of ID preferably with a birth date, but at least a photo. Including a a student ID. Most bar staff will likely accept it with a recent expiration.

Asking for a second ID, credit card with the same name etc is basic response for a suspicious ID. Straight out of alcohol safety training courses. It's as much about seeing if you choke, panic, or make an excuse as actually confirming an ID.

But your ID is good till tomorrow. There's nothing suspicious about an ID that's going to expire.