Hello all,

I am trying to find a solution to the following problem:
In column E, various arrival times can be entered and in column F, a letter needs to be chosen from a dropdown menu (A, S or T). After entering the arrival time and choosing the corresponding letter, Column I needs to show a timer/countdown. For example:

Expec | Arriv | ? | TIME LEFT
08:30 | 09:00 | A | [Countdown of 48 hours]
09:00 | 09:25 | S | [Countdown of 24 hours]
10:00 | 10:15 | T | [Countdown of 4 hours]

I can not seem to get the countdown working real time. After doing some extensive research I think there are two options:
The first one is to put somewhere a real time dynamic clock, so I can calculate a deadline for example and subtract the real time dynamic clock from the deadline. The only problem I have now is that I need to manually refresh (F9) every second....

The 2nd option is to build in a timer after entering the arrival time (and choosing the letter). I have found a few examples of countdown timers online, however, most of them, when you execute, all the times in the whole excel file are counting down or they don't work after entering the arrival time or it can not handle different countdown timers in each row.

Is there anyone that can help?

Many thanks in advance.