duration type issue

[and78]

my table is linked to a google spreadsheet that a a duration column: 1.24 means 1 hour and 24 minutes.

i try to define on app sheet a correspondant column, but the definion of duration is not customizable; so it appears that it has only the ":"  colons format. it lacks the "." dot separator. So i can only insert 1:24 value

it is not accepted 1.24. 

how can i define a field properly like : "HHH.MM"? 

[Marc_Dillon]

Appsheet duration values are always of the format "HHH:MM:SS". Your data must match this.

[TeeSee1]

To add to @Marc_Dillon 's comment, @and78 , it sounds like you are entering duration data directly into the spreadsheet.

Should you be using the AppSheet UX to enter data? A lot of things do not work if you enter data directly into the underlying spreadsheet. You might want to consider how date entry (perhaps how the user interacts with your 'system') is made.