Having a small lawn in the front yard only is a blessing for us being surrounded by big trees who want to suck up any water from any plant at any given time. Because of that, we keep our St. Augustine on the long side, 5-6" tall, mow more frequently and water less frequently and for longer and deeper. The longer grass shades the soil and helps to keep it moist. I also use a mulching mower to help as well. I love my healthy lawn. But it takes effort to keep it weed-free and green.
We are lucky to be out of drought conditions but know all too well what it's like to work around the City's given watering schedule. Timers help with that to give every plant a drink when allowed even when you should be sleeping. But the best time of day to water is early morning just before the sun comes up.
In June, I am going out to San Diego to help my DD with her lawn of weeds. Having a huge watering restriction, more like no watering at all, this will be a challenge to help her make her yard look nice again.