For transit buses belonging to transit agencies listed on this site, does the year listed with this bus mean the actual calendar year it was delivered and entered to service in most cases?

I pretty much answered this question in your last thread. Yes. Delivery date. Not model year. Unless there's a VIN.

Please do not open new threads when you can allocate one thread for whatever question you have on the same subject. Your questions are all very similar (verging on asinine) and if you keep asking them over and over they're bound to be viewed as spam so please don't do that.

I was NOT bullying.

I never said that you did, just that you opening up several threads at once is not very good forum etiquette.

How is it not that good of forum etiquette?

It makes you come across as impatient.

I'm guessing English is not your first language and that you are using a translator?

The answer to your question is on the FAQ page:

"How are selected the years of the vehicles?
For lots of US cars it is quite easy: some details allow to find the exact years. But for other cars it is impossible, so we put the year when the car model was released. For some vehicle the date may be wrong, or we may have missed a detail that allows a more precise identification of the year. In that case, do not hesitate to notify this (see above in the "I found an error/misnamed vehicle" section)."

Since most trucks and buses use the same body style for several years, we usually put in the first or oldest possible year.

There are other websites that list specific years for buses in transit systems. If we match the ones listed here to that list, then that year is used.

As far as model year vs. calendar year listing, that varies by country. And even then it may not matter, as most truck/bus manufacturers make changes as needed and not for the new model year. Model years are more of a marketing idea to sell automobiles in the retail market, not necessarily for commercial sellers who handle fleet sales.