Rioghán

[Babyboyno2]

Got this into my top 3. Just curious of how people would pronounce it, is it “REE-ON”

Lots of historic mentions of Dáire.
St Patrick was given land by one.

There is also Daighre, and Dathal.

Some do spell it Dáithí. Dáithí Ó Sé does for one, and he's a from a Gaeltacht area. The pronunciation seems to match the no fada spelling better though, or at least the local pronunciation where I am does.

Daire is mostly spelt without a fada now in my experience, and that matches the usual pronunciation, but the name did have a fada in Old Irish and some people do still use it.

I don't think ái is always pronounced like in Máire.
Sometimes the i is only there to make the consonant slender and it doesn't affect the vowel.
bán (blank/ white)
báine (blankness/whiteness)

I think Learner Dialect exaggerates the effects of the consonant changes on the vowel. It's not as if it's not possible to say Dáithí as "Daa-hyee".
(Apologies to non-pedants.)

The fada would make it daw-hee rather than doh-hee though surely. (Doh as in the start of dot, approximately, rather than dough.)

I think it was a pp said Dáithi would be pronounced like Máire if there were a fada on the a, not me @PuddingAunt.

i don't think they'd sound the same, and agree not all vowels are there to be pronounced as such, but there is a difference between á and a usually - though á doesn't make the 'aw' sound in Ulster that it does in Connacht and Munster anyway. So it depends where you are too.

Thoughts on Callan “Cal-an” online says Irish and Scottish name and it’s simple to pronounce, really liking it atm

I've never heard of Callan used as a first name to be honest. Only as a surname and the name of a town (in Co Kilkenny).

Just checked the CSO baby names site and there have been a few over the years with a high of 18 in 2012, but it's rare. Even in 2012 it was ranked 267th in popularity.