Leave to Enter

[NJT]

Hello all. I have a question I'm sure one of you will be able to answer.

I am a Canadian citizen, currently in the UK. My 6 months Leave to Enter runs out in late April. At that point I will have been here 6 months, my question is, Is there a set amount of time I must remain outside the UK before returning?

I was planning to go back to Canada for 2-3 weeks, then return.Will I be refused entry? I have heard after your 6 months is up, you must remain outside the UK for 24 hours, I've also heard 90 days and I've heard 6 months, any of this true?

Thanks for you time.