Must have flown that type of aircraft within the last 28 days. Doesn't matter how long for. There are certain exceptions, for example if you've flown a Warrior within the last 28 days they will let you fly a Cherokee, so long as you have flown a Cherokee at least once before.
Outside the 28 days, it's up to an instructor. I flew once when I hadn't flown anything for 29 days. The instructor decided there was no need for a checkout at all in that particular case.
Once you have more than 100 hours, you can apply for a "green card", which increases the currency rules to 56 days. The requirements for the issue of a green card are entirely at the discretion of either the CFI or the Deputy CFI.
This type of rule is very common, the details of it vary from one club to another though.
FFF
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