Hi @Fiala
Using your sheet as an example, you will need to split the date into an array and reformat it. The time will also be sent to your flow as a float and needs converted to a time too.

Compose: split(item()?['date'],'.')
Start: @{outputs('Compose')?[2]}-@{outputs('Compose')?[1]}-@{outputs('Compose')?[0]}T@{formatdatetime(addseconds('1899-12-30',int(formatnumber(mul(float(items('Apply_to_each')?['Start Time']),86400),'0'))),'HH:mm:ss')}
End: @{outputs('Compose')?[2]}-@{outputs('Compose')?[1]}-@{outputs('Compose')?[0]}T@{formatdatetime(addseconds('1899-12-30',int(formatnumber(mul(float(items('Apply_to_each')?['End time']),86400),'0'))),'HH:mm:ss')}
In a bit more detail, you build a date using element 2 1 and 0 from the array created by splitting the date on the '.'
Format the time using an expression to calculate a date time, but use a formatdatetime expression of HH:mm:ss (note that capital HH means 24 hours).
The result is as follows:

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Cheers,
Damien
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