Set hours? How does that even work? I've never heard of set ToT hours...
I do think the LW was ridiculous and in the wrong though. First off, in my experience many kids, especially younger ones, ToT while its still light out or just at dusk, once its full dark they lessen and after 8 its almost none, after 9 is very rare (and unlikely to yield a door opening so impractical on the part of the kids).
All kids know that there are clues to look for - decorations, porch light on, etc to see if a house is welcoming of ToT'ers. All the LW needed to do was take down her door decoration, close her blinds and not have the porch light on and not answer her door. Later, after she'd eaten, she could put out the decoration, light her light and open her blinds with lights on inside and kids would know she'd answer.