I have now made my homework regarding Format codes and now all your advices works for me. BUT as you said, my users did not like that their data were changed and they got confused when they wrote one thing and something else were displayed. That was especially true when I used the format [hh]:mm and their entered seconds disappered. I think I have to try something..
The 3 input cells sounds OK if that was used from the begining. They have used the format hh:mm:ss for so long that they do not want to change to another method and they want Excel to display what they enter and nothing else. I found out that "Data validation" treated #Value! as False, so I could skip all IsNumeric tests. My function got smaller

=AND(LEN(B14)=8, MID(B14,3,1)=":", MID(B14,6,1)=":", AND(VALUE(MID(B14,1,2))=0,VALUE(MID(B14,1,2))<100 , VALUE(MID(B14,4,2))=0,VALUE(MID(B14,4,2))<60, VALUE(MID(B14,7,2))=0,VALUE(MID(B14,7,2))<60)

Is their a better way to check if a value is between 2 values than AND(VALUE(MID(B14,7,2))=0,VALUE(MID(B14,7,2))<60) )

ISERROR(VALUE(MID(B5,1,2))) seems to be a lot of code to check if it is a number. Is their a better way to do it

Regard
/Nikla

----- arno wrote: ----

the only trouble i see is that the entered time is lost and replaced by
"date". instead, you could have 3 input cells (hr, min, sec), each with dat
validation set to <60 or <100. this also denies entereing characters

then you can calculate the time with a formula without annoying the user
that input the data. make sure you set the format to [hh] and rememder tha
times are a fraction of a day, like 1,5 equals 36:00:00

arn





"Niklas" schrieb im Newsbeitra
..
The highest time Data Validation accepts is 23:59:59 or have I misse
something
Regard
/Nikla
----- arno wrote: ----
Hi Niklas
In a text cell I want to check if the user have entered a vali
interval
A valid intervall looks like this 33:01:00
why don't you use a cell that is formatted as time, [hh]:mm:ss? the
yo
only have to validate data (menu Data) to be less than the "time
100:00:00
regard
arn