british english - Can any time on clock be spoken as it is in numbers only (hour + minutes)?

According to the Cambridge dictionary, the answer for “What time is it?” depends on the minutes.

When the times outside five-minute intervals, we say minutes past or minutes to:

9.01 one minute past nine

9.03 three minutes past nine

9.36 twenty-four minutes to ten

9.58 two minutes to ten

Otherwise, we can say directly what we see on the watch / clock, it says to read it simply. For example:

9.05 five past nine or nine oh five

9.10 ten past nine or nine ten

9.15 quarter past nine or nine fifteen

9.20 twenty past nine or nine twenty

9.25 twenty-five past nine or nine twenty-five

Can we say times out loud by the actual numbers that are on the watch / clock and maybe these Cambridge rules are only in the UK? According to what I remember, many times when I asked people about the time, they didn't follow those rules. They would say: 10:13 = Ten thirteen. 8:21 = eight twenty one etc. If that is correct, then what about 10:11, 10:10, 9:11 — if I simply read them as they are (Ten eleven), it works?