Looking on the internet deeply has found these results:

on my holidays is the most popular phrase on the web.

in my holidays 1325,000 results on the web	on my holidays 1349,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
You know, if I'd wanted to spend my holiday in the library I could've walked 10 blocks to 42nd Street. Statue in Gorky Park, national holiday in my name, I can remember my first flight, or my holidays in Britain. I've spent my holiday in prison, but I must go back to Sweden! Manny, I am not going to spend my holiday in a snake pit. I have been brought back from my holiday in California to sort it out. If I'd wanted to spend my holiday in the library... Gentlemen, it appears my holiday shopping is done.	Relied on that money for my holiday. I went there once with my father on holiday. I was on holiday with my husband and he was taken. I was going on holiday with my family And here. You're the first on my list, Holiday. And right now you're just a couple of stale nuts on my holiday fruitcake!

in my holidays

1325,000 results on the web

on my holidays

1349,000 results on the web

More popular!

You know, if I'd wanted to spend my holiday in the library I could've walked 10 blocks to 42nd Street.
Statue in Gorky Park, national holiday in my name,
I can remember my first flight, or my holidays in Britain.
I've spent my holiday in prison, but I must go back to Sweden!
Manny, I am not going to spend my holiday in a snake pit.
I have been brought back from my holiday in California to sort it out.
If I'd wanted to spend my holiday in the library...
Gentlemen, it appears my holiday shopping is done.