So you have a 12-hour layover during midnight and midday?
Apart from possibly having some shisha and food somewhere, there won't be much to do. Al Shami is open 24 hours, on Al Salwa Road; Most restuarants close around 2am, apart from a few like Al Shami. Grand Joud Cafe on Al Salwa has 24 hours shisha too.
If you had a DAYTIME layover, it would be different.