One way:


A2: =A1 + TIME(0, 15, 0)

or

A3: =A1 + TIME(0, 0, 15)

In article ,
"Michael H. Cox" <Michael H. wrote:

How do I add time to cells? i.e. I have a start time 14:58 on the 17th of May
and I need to create a column with each subsequent cell containing a time 15
min later or 15 seconds later.