Frame range for Render layers how to set frame range for layers. for example layer 1, start frame should be 1 and end frame should be 10. layer 2, start frame should be 20 and end frame should be 35.
You can animate layer's Disable or Enable using I.

Set keyfrimes like you set keyframes for object visibility:

For example, for start frame on the 20th and end on the 35th, you should set 3 keyframes: off - anywhere before 20 frame, on - on the 20th frame, off - on the 35th frame