| First | Second | Result |
|----------+-----------+-----------|
| 00:00:00 | -00:10:10 | -01:49:50 |
#+TBLFM: $3='(+ $1..$2);T
| First | Second | Result |
|----------+-----------+--------|
| 00:00:00 | -00:10:10 | -0.17 |
#+TBLFM: $3='(+ $1..$2);t
| First | Second | Result |
|----------+-----------+-----------|
| 00:00:00 | -02:01:00 | -03:59:00 |
#+TBLFM: $3='(+ $1..$2);T
| First | Second | Result |
|----------+-----------+--------|
| 00:00:00 | -02:01:00 | -2.02 |
#+TBLFM: $3='(+ $1..$2);t