Calculating sum of duration for values that vary (not chronological)

[MATC]

Hello,

I've encountered an issue where I need to calculate sum of durration (e.g. for a day) for specific ID's (user can select whatever they want) 

On given table I have 2 values that are occupying the same time slot and sum of their duration is calculated to be 51 sec but in fact they are occupying only 31 sec. Is there a way to correctly calculate this on the front end (as user can select multiple different distinct ID's)
Here's another example of given selected data 

Correct duration is 5:11:33

[rubenmarin]

Hi, you're right, that complicates the calculation on the chart. Could this be done in script? That would mean that you'll have a precalculated value by date and selections won't affect that precalculted value but otherwise I see too many cases that could complicate (or even make not possible) the chart expression