Everyoone talks about the traffic in new dehli that does hinder getting to the sites of interest to tourist. One thread talks about Sunday being light, but if everything is closed on Monday: why would Sunday be the lightest traffic day

Sunday is the lightest traffic day. I'm guessing that you mean that tourist sites are closed on Monday in Delhi - businesses are open.

we did not find that traffic hindered any of our movements in delhi...

Daytime travel should be fine on any day. Just avoid the morning and evening commute hours.

On a Monday I was surprised at how much I was able to see in Delhi the morning hours. The Red Fort was closed on Monday.

Humayun’s Tomb had hardly any visitors at 8:30 am. Qutab Minar was not crowded either.

I went to old Delhi before noon and was told after noon it is nearly impossible to drive around there.

Early Sunday morning had some of the least traffic.