Simple, very stupid, Q re British Govt System

In the UK I understand that a Prime Minister may lose the confidence of Parliament and, losing a vote of confidence, his/her Government may fall at any time regardless of whether there was an election or not.

But what I don’t understand very well is how the timing of elections are decided …

A. I get the strong impression a PM may call elections at any point to maximize her/his advantage is that correct?

B. Assuming “A” IS correct, then how often must elections be held? IS it on a regular timed cycle or …. What?

I believe elections must be called after five years in office. Most PMs try to hold them before that point, and while their popularity is high.

No more than five years may go between elections. And, yes, a prime minister may call for an election at any time up to five years. No, there is no regular time cycle like we have of a four-year cycle in the U.S. When a vote of no confidence passes, the Prime Minister has some particular amount of time (a month? three months? I forget) in which to call for an election.

…and yes, the ability to call an election is used very cynically. It’s not unusual to see one of two tactics:

[1] Hint that you’re going to call an election, force the opposition to spend their entire advertising budget, then wait a bit longer to call it and blitz them publicity-wise.

[2] Announce tax cuts just before you call an election.

The second tactic is a bit more risky, since people don’t like feeling they’re being conned.