How to write a time calculation formula in EXCEL?

Question

excel

The authorities introduced a new fad for all employees of the technical support department, they consider that we do not work much, it is necessary to create a daily detailed report in the format:
process \ task description
start
time end time
duration
could make a primitive calculation of subtracting the start time from the end time,
but let's say I filled in the time in advance and I want to make adjustments to a specific task and you have to manually cut all the columns over time. Is it possible to implement the formula so that if I am allowed to change the time in a certain place and add 10 minutes and the time shifts accordingly for all columns? It just infuriates me to spend time on such nonsense and I want to automate it as much as possible.
Or, as an option, I have a list of typical tasks that have accumulated during the reporting period and set a certain time spent for each task, and when inserting such a task, the time would be set automatically based on the specified work schedule, for example, from 9 to 18 or from 10 to 19. Although so composing the question, I begin to understand maybe I want too much from EXCEL ... I will be grateful for any answers and advice.

Answer 1

If it infuriates you to spend time on such nonsense, change your job)
In excel:
select a column, properties-formatting-all formats - DD.MM.YYYY hh: mm
enter the date and time in the first line, in the second, in the third write = 1 cell-second
you get something like 01/02/1900 3:47 - this is the time difference in excel date-time format, playing with the formatting for this cell (removing months and years, for example), you can achieve a beautiful display of the delta. See the help for all formulas for working with date and time, you can add at least 10 minutes, at least 10 years.
What you are asking for below is also done via formulas or via macros. Personally, macros are more convenient for me, but they need to be studied, and through formulas, use logical constructions and formulas of the "references and arrays" category (click on the cell, at the top left of the input line, click on the function icon, there will be a list of all functions)

Answer 2

You can also view the Gantt chart here .