Correct way to write 24 hour-time? Decimalpoint too.

(1) I see several worthy attempts to write the time in a 24-hour
format. Does a definitive format exist?

I want to leave out the seconds. Also note that I am NOT referring
to computer conventions of any sort.

QUESTION: If it is 11 minutes past six in the evening then what is
the correct format?

1816 hrs
18:16 hrs
18:16 hours
18:16 h
18:16
18.16
18-16

Does it vary between being written by a word processor and by hand?
See below.

(2) What is the correct way to write a decimal point? I am English
and that means that a comma is not the correct symbol for the decomal
point.

But ISTR that when the decimal point was written by hand it was in
the air about half the height of the digits. Typewriters and word
prorcessors did not offer that half-way character so a full stop was
used. But is it more correct to handwrite the decimal point as half
way up the height of the digits?




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posted to 3 groups whose members probably
need to be accurate about time recording