Is min_created strictly increasing, or can you retroactively create things?

[Dan]

I'm currently looking at findAllShopReceipts, but I guess this
question applies to anything that takes a min_created parameter.

Let's say I want to periodically pull down a shop's receipts. On March
1st I got all available receipts at that time, and the most recently-
created one was created on February 26th (I'll use normal dates here,
but I'd convert them to epoch notation for all API calls).

On April 1st, I'd like to update and get all results created since the
last time I updated. Would using min_created=Feb 27 (to save on API
calls) get me all receipts, or is it possible that a user could create
a receipt back-dated to before that date, which I'd miss if I used
min_created?

Thanks,

Dan