Throwing a retirement send-off in your neighborhood brings everyone together for a great night, but private rooms and catering minimums add up fast. Booking on a Tuesday helps keep costs down, since restaurants are quieter and more flexible with pricing. Give yourself a few weeks to lock down the headcount and menu before you put down any deposits.
Timing is everything when you are organizing a group dinner. You want to lock in the private room early so you actually get the space, but you can wait on finalizing the exact head count until the week of the event. Spreading out the fixed costs helps keep your own bank account from taking a sudden hit all at once.
Remember that the 0% intro window is a deadline, not free money. If you still have a balance left on the Discover it® Cash Back when those 15 months are up, interest will kick in on what you owe.