In Ireland we say:
"Twenty-five to ten" (9:35) (21:35)
"Twenty to ten" (9:40) (21:40)
"A quarter to ten" (9:45) (21:45)
"Ten to ten" (9:50) (21:50)
"Five to ten" (9:55) (21:55)
"Ten o'clock" or just "Ten". For example, "I'll see you at ten so!" (10:00) (22:00)
"Ten past ten" (10:10) (22:10)
"A quarter past ten" (10:15) (22:15)
"Half ten" and sometimes "Half past ten" (10:30) (22:30)
You can also drop the hour value, if it is obvious, for example:
"Is it half past yet?" (you can't say "Is it half yet?")
"It's a quarter to, I must go!"
When being exact:
"It's a minute past nine" (9:01) (21:01)
"It's thirteen minutes to ten" (9:47) (21:47)
a.m and p.m. are not used. Instead to differentiate between 9:35 and 21:35 you would say:
"I'll see you at twenty-five to ten tomorrow evening so."
"I'll pick you up at twenty-five to ten in the morning."
This is very consistent for all age groups and all parts of Ireland as fas as I know.
How do you tell the time and mention which dialect you speak in your answer? How much of the Irish way of telling the time would sound alien or even confusing to you?