3 different times

I have to go through logs all day and line up three different time sources.
If I could change one of the times, and have the other two change accordingly , my life would be so much better.

Please help !

What do you want the times to do when you make a change?

if I change any of the times, I would like the other 2 to change. IE if one cahnges by 7 minutes, I would like all 3 to display the additional 7 minutes

What I have is 3 different machines that all have their Time of day set to different values.
When I start analyzing problems , the first thing I need to do if figure out the time difference between all 3 servers. So what I do is write down the time of all 3 servers at a known point in time. I then have to look through the logs from all three servers that display their own time in their logs. What I am looking for is a way to input the time of server A in A1, the Time of Server B in B1, and the time of server C in C1. Then if I change the value of the time in A1, I would like the time to change in B1 and C1 to match the time difference, so they are all showing the same point in time. And same for B1 and C1, If I change any one of the times, I want the other 2 to line up.