I'm kinda new to this site so I'm not entirely sure how the format works.
In the sentence below, which I'm assuming I translated correctly as "When I was in high school, I studied often":
some people tend to add に after ころ when I looked it up. Is it necessary and is it wrong to have/not have the に particle in the sentence? I'm fairly certain that the に particle is used for destination/certain time reference among other things but I don't see why it's more common to not have it at the end of ころ while some people actually do
Also, I didn't know if I can include a separate question since I didn't really want to make a whole new thread for it but is it wrong if I were to say「高校でいるのころ」 instead of 「高校のころ」 to be more specific?