My April/May hatches usually start laying around fall Sept/Oct. while the older hens are molting.
When I hatch Sept./Oct. those pullets don't usually start laying until March and April. These last that I hatched September 17, 2015 have just begun laying. There are 3 or 4 that have started as of today.
I'm so glad you said this because it forced me to go back and check my hatch dates and I confused two of my hatches. The batch that started laying in November was hatched in June, and the ones I hatched in September starting laying in late January. I stand corrected.