Calculate the number of days between two datetimes?

How to calculate the number of days between two datetimes?

days(between(day1,day2)) does not work:

"Error using days (line xxx) Input data must be a real, numeric array."

Answer 1

[Brendan Hamm]

You can do:

days(day2-day1)

The issue is that the between function returns a calendarDuration and this is measured using variable time-frames like months and years which contain different numbers of days.

Answer 2

[Peter Perkins]

between already calculated the difference between those two dates in days:

>> d1 = datetime('yesterday'); d2 = datetime('tomorrow');
>> between(d1,d2)
ans = 
  calendarDuration
   2d

Even more explicitly:

> between(d1,d2,'days')
ans = 
  calendarDuration
   2d

If you then want the number 2, use caldays:

>> caldays(between(d1,d2,'days'))
ans =
     2

Hope this helps.

[Jussi Ikäheimo]

It seems that the 'days' option is needed in between(), otherwise an error results.

[Peter Perkins]

Jussi, I'm not sure what you're saying. All I wanted to demonstrate was that between gives you back a quantity that already measures the number of days. If you need a numeric value, then caldays is the function you want to apply to that, not days.