Start time and End time Calculation sheet and uneditable of Time

Hi,

Can someone help me with a sheet which will show start time and end time in seconds. I mean when I enter Shift+Ctrl semicolon will give me the time(hh:mm) and after few seconds if enter the same it gives me same format time(hh:mm). I am manually changing the format into MM:SS. Simple I need a spread sheet where I can capture start and end time accurately.

I have a team who work on a task by time based, every second counts.

2nd Question- I want the time format uneditable, it should not allow me to make the changes on the time entered.

Hello,

I am new to this forum and not advanced in Excel but I have had this same problem in the past, I believe. Here is the solution I used.
Instead of trying to track time in different increments, hh:mm, try using only one increment...seconds. Example, if a race takes 2 minutes and 28 seconds or 2:28, convert it to all seconds 148 seconds.
Hope this helped.