Same here. And when you check the word itself, it is a different pronunciation ending with an "a"
I have the same question. I know о is often pronounced а, but I didn't know the opposite is possible too.
Confused. When I click only on марта it says "martA", but when I click on the audio symbol for the whole phrase it says "... martO"
It would mean "March has started [something]". "Начал" is a transitive verb so it requires a grammatical object. "March has started [itself]" would be "начался март".
Could you clarify your question, please? Considering that "of" is an English word while "начало" is a Russian word, one can be pretty sure they are not used together in any form or shape.