# Number of days between 2 dates

Paul Looney simplsol at aol.com
Wed Apr 16 14:28:23 EDT 2014

```JBV,

One of the date issue you run into on OS X is that it has 23 hour and 25 hour days - when going from or to standard time.

Here is a solution I've been using for many years:

function ahsm_DaysBetweenDates firstDate,secondDate
# Calculates the days elapsed between two dates, entered in any order.
# Use "abs" in case the first date is later than the second.
# Use "round" & numberFormat "#." in case there is a fraction
# created dividing 86400 into the non-24 hr days
# beginning or ending Daylight Savings Time.
# Add 1 to the date to include both the first and second date,
# (if they are the same, it is one day reviewed - not zero days).

set the useSystemDate to true -- for international dates
--convert firstDate to seconds -- did not work with non-US dates
convert firstDate from abbr date to seconds
--convert secondDate to seconds
convert secondDate from abbr date to seconds
put abs (firstDate - secondDate) into vLapsedSeconds
set numberFormat to "#."
put round ((vLapsedSeconds/86400)) + 1 into vDays
return vDays
end ahsm_DaysBetweenDates

Paul Looney

On Apr 16, 2014, at 9:25 AM, jbv at souslelogo.com wrote:

> Hi list,
>
> I need to calculate the number of days between any date and
> january 1st of the same year.
> So I tried this :
>   put "1/31/14" && "0:00 AM" into tdate
>   convert tdate to long seconds
>   put "1/1/14" && "0:00 AM" into date0
>   convert date0 to long seconds
>   put (tdate - date0)/86400
>
> which seems to work and returns an integer.
> When I try this as 1st line of my script :
>   put "3/30/14" && "0:00 AM" into tdate
> it still works (returns 88).
>
> And suddenly, the following :
>   put "3/31/14" && "0:00 AM" into tdate
> returns 88.958333
>
> Any idea ?
>
> Thanks,
> jbv
>
>
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