Laravel / Carbon adding two timestamps together?

Question

I am working on a system where people can start and stop something which calculates the time it has taken them. This is done by:

• When the "Start" button is pressed, a date is added into the database table for that row.

• When the "Stop" button is pressed, a date (end date)is added then I calculate the difference by:

  $startTime = \Carbon\Carbon::parse($task->date_start);
  $finishTime = \Carbon\Carbon::parse($task->date_complete);
  
  $totalDuration = $finishTime->diffInSeconds($startTime);
  

And also "timeSpent" $totalDuration is stored as a timestamp.

The requirements have changed so that the user can stop/start but it still holds the the total time. My idea is:

With the same process as below, the timeSpent is always stored, so if a user clicks start/stop again I can just calculate the difference as done previously and then add it to the timeSpent that is stored inside the database, however I can't seem to figure out how to do this. I have tried:

$totalTimeSpent = strtotime($task->time_spent) +
strtotime($totalDuration);

Then parse it again:

$total = \Carbon\Carbon::parse($totalTimeSpent);

But this throughs up an error:

Failed to parse time string (1463184003) at position 7 (0): Unexpected character

Can someone suggest an alternative?

Answer 1

You shouldn't store $totalDuration in a field with type timestamp because it's not a timestamp. It's just a number of seconds and should be stored in an integer field.

Once you use integer type for that, you shouldn't have any issues with adding the numbers:

$total = $task->time_spent + $totalDuration;