For the following JavaScript, I was expecting output to be 1 but it is not, any explanation?
var startDate = moment('2018-01-01');
var endDate = moment('2018-12-31');
moment.duration(endDate.diff(startDate)).asYears()
0.9965981505438167
What start and end dates would give 1 full year?
It is because diff gives you the differences in milliseconds and then recalculated in years, giving you the 0.99.. value
In order to get a difference in years you can do this:
endDate.diff(startDate, 'year');
and you will get 1 as wanted
Try this, maybe you can understand.
var startDate = moment("2018-01-01").startOf("day");
var endDate = moment("2019-01-01").startOf("day");
// var endDate = moment("2018-12-31").startOf("day"); try this also.
console.log(startDate);
console.log(endDate);
console.log("--------------");
console.log(endDate.diff(startDate, "days"));
console.log(endDate.diff(startDate, "years"));
console.log("--------------");