Here is a quick reminder to make sure you know what kind of sprinkler heads you have in each zone.
Its very common for people to set all of their turf irrigation zones to run for the same amount of time. This can be a big mistake if you have some zones with rotor heads and others with spray heads.
On average, rotors put out .5 to 1 inch of water per hour. On the other hand, spray heads put out 1.5 to 2 inches of water per hour. 15 to 20 minutes for spray heads is probably plenty...but your rotors need to be running 2-3x longer.
Have a zone with both rotors and spray heads? Unfortunately there is no way around it, you need to contact an irrigation company and get that corrected. You should NEVER mix different types of sprinkler heads on the same zone!