Date night doesn't have to be expensive or even at night!
Consider things like:
* breakfast in bed
* taking a drive and talking
* taking a walk for ice-cream
* walking through the mall and window shopping
* putting on music and just holding each other on the couch
* riding bikes
* playing a board game
* watching a sunset and eating take-out
The important thing is taking time away from the other people and responsibilities in your world to focus on each other. If you find yourself being irritable at each other, it may just be that you have not had a lot of one-on-one time together in a relaxed atmosphere.
What are your ways of spending time with your mate?