Sunny spells v sunny intervals v sunny periods - which is longest?

[RustyBear]

I've tried googling but nothing seems to make it clear. Today my weather app says 'lengthy sunny spells', tomorrow and Monday are sunny spells, but not lengthy, Tuesday & Wednesday are sunny intervals, then it's sunny spells again until it rains on Saturday. I've also seen sunny periods, though not in the two weeks my app covers.
So, weather experts, is there an official definition of when each should be used?

Now this is the question I never knew I needed to see answered! Watching with interest.

I don't think there is an official definition.

I was so excited by the notification! Can you make one up for me please?

ok, there's a film called Partly Cloudy with Sunny spells which lasts 95 minutes. So a Sunny spell is defined now as 95 minutes long.

A football interval lasts 15 minutes. So a sunny interval is 15 mins.

Googling Sunny Period comes up with a menstrual cup that can be worn for 12 hours, but that seems a bit long!

Digging around, there might actually be official definitions after all, but I have no clue!

Hong Kong Obervatory says this.

This is superb. Thank you!

I have visions of meteorologists now quietly weeping.

Thank you OYBBK!🌤⛅️🌥

Great emojis RB!