If you are replying to a previous message, it is always wise to quote enough
of the previous message to put your reply into context.

In this case you are replying (I believe) to the suggestion of using:
=ROW(A16)&":00-"&ROW(A17)&":00"

You might therefore want to develop the above suggestion into:
=INT(ROW(A64)/4)&":"&TEXT(MOD(ROW(A64),4)*15,"00")&"-"&INT(ROW(A65)/4)&":"&TEXT(MOD(ROW(A65),4)*15,"00")
--
David Biddulph

"YO" wrote in message
...
it worked great! thank you very much!

perhaps you can further help me.
how can i do the same with quarters of an hour? :
16:00-16:15 16:15-16:30 16:30-16:45 16:45-17:00 17:00-17:15...

thank you