Hello,

my sugar is ent 6 and i am wondering how to implement the following functionality.

I want in cases to have a field that will ask user how many minutes or hours he spent working on case, and to have that time added to previous value, he or somebody else entered.

For example,

X user opens case and he worked on case 15 minutes. We remember 15 minutes in db.
Y user edits case and he worked 30 minutes on case. We take 30 minutes and add them to previous value +15 so in end we get 45 minutes in db.

Now i know how to write logic hooks but i never worked with time values or datetime, so a little help on how to implement this best way would be great.

Thank you.