calculating work experience with momentjs - datetime

Question

I am trying to figure out how to best calculate work experience using momentjs.
Let's say I have had the following jobs:
from december 15. 2013 - march 15 2013
from february 20. 2013 - june 1. 2013
from september 1 2013 - december 1 2013.
as you can see there is an overlap between job 1 and 2, and there is a gap between job 2 and 3.
The challenge is that i just can't calculate the difference between the start of job 1 and the end of job 3, since there is a gap between job 2 and job 3.
On the other hand I cannot just add the timediff for each job since there is an overlap between job 1 and job 2.
Any input on how to tackle this the best, is appreciated.
thanks,
Thomas

Answer 1

This problem is unfortunately not solvable with moment.js. But I wrote a simple solution for you, using integers as start end end values:
calc_duration = function(list) {
// calculate the duration and add it to the list elements
// when you are working with you need to adjust how x.duration
// is retrieved
list_with_duration = list.map( function(x){
x.duration = x.end - x.start
return x
}).sort( function(a,b){
return a.start > b.start
});
// sums all the durations together except for overlapping dates, there it
// will only add the time span of the second date that exclusive of the
// first date
total_duration = list_with_duration.reduce( function(sum, curr, i, list){
if (i == 0 || list[i-1].end < curr.start ) {
return sum + curr.duration;
} else if ( list[i-1].end > curr.end ) {
return sum;
} else {
return sum + curr.end - list[i-1].end;
}
}, 0);
return total_duration;
}
calc_duration([{start: 0, end: 10},{start: 5, end: 15},{start:20, end: 30}])
//returns 25
calc_duration([{start: 20, end: 30},{start: 5, end: 50},{start:0, end: 10}])
//returns 50