I did this with my son, and we still do it every so often. Just know that the 12 weeks off will not turn out the way you have planned. No one prepared me for my 2nd because it's much more than double, and it was so hard to balance spending time with the two. Just be prepared for it to be more than doubling your mommy duties. Take advantage of this time where he is the only one.
Wed nights are kids night at Rainforest Cafe. I think it's 1.99 for a kid meal. Usually we eat and leave paying about $14. He loves it. We also spent time beforehand making crowns and decorating with all kinds of stuff (glitter, jewels, markers, puff balls, etc). Mine says princess and his says king (he thinks prince sounds like a girl LOL). He wants us to wear them everytime we have date night, so we do. It felt funny at first walking through the mall with people staring at us, but he was proud of our crowns, so I was proud too.
Our dates are usually dinners out, and Rainforest is usually the winner. BUT Molly's is kids free night on Wed and so is Ted Es Burgers on Wed. Incredible Pizza (Lidos now I think) is very inexpensive and everything is half price on holidays (like valentines day). Games are half price and so are meals. Tuesday nights are kids nights at Samurai Bistro, which is pretty cool, but warn him about the flames at the beginning because it might scare him. Mine was scared because I didn't warn him beforehand. I know there are more, but those are a few.