In article <a5a4659c4c.B21306@...>,
<B21306@...> wrote:
> --------------------------
> def proc age_show

> if r_froster_card.g_date <1
> r_froster_card.g_age = 0

> else

> r_froster_card.g_age = (@date-r_froster_card.g_date)
> endif

> if @date < r_froster_card.g_date
> r_froster_card.g_age = 0
> endif

> return r_froster_card.g_age

> enddef

> ------------------------------------------------
> I will look for a another solution again.
> Thank You very much for Your help Wim !!

It looks to me Hans, that with your formula of

(@date - r_froster_card.g_date)

you are trying to subtract one date from another date. The answer does not
(usually) make sense, because S-Base will format the result as a date
also, based on a starting date of 24th November -4713. For example, if I
try to subtract the first of January this year from today's date I get

print (@date - @timefoy(@date))
02/03/-4712

instead of 99, which is the number of days between the two dates.

If you use @int(@date - r_froster_card.g_date) instead, you will force the
^^^^
result to be an integer, which you can then manipulate as you wish.

I have never been able to get the data-type sub-type (time/date interval)
to make any sense. On the occasions when I've needed to display a time
interval, I have usually found it best to extract the difference in days
(as above), then convert that into a string such as "00y 04m 09d" or
however you want it using my own function depending on what I want.

I have attached a couple of functions to this email for you to try out.
They are attached rather than included within the body as some of the
lines are a bit long, and may get formatted into multiple lines by your
email reader. Both the functions can be made much shorter once you
understand how they work.


> A Happy Easter for All say

> Hans-Juergen Barthelmehs

A Happy Easter to you too.

Regards,

--
Robin Hampshire
robin@...

| this function assumes that all calendar months are of thirty days
| and that there are no leap years. It is rather crude and inaccurate
| over long time intervals.
| returns a string representation of a number of days converted to
| years, months and days
def proc time_interval(diff_days)
local int_str = ""
local years = diff_days // 365 , residue = diff_days % 365
local months = residue // 30, days = residue % 30
if years then int_str = @str(years) + "Y "
if months then int_str += @str(months) + "M "
return int_str + @str(days) + "D"
enddef

| this function will find the number of years, months and days between
| two dates, regardless of which date is the earlier.
| "inclusive" should be TRUE or FALSE depending on whether the difference
| should be inclusive or not (i.e. do both dates "count" towards the total).
| returns a string representing "xxY xxM xxD"
def proc time_interval_exact(date_1, date_2, inclusive)
local int_str = ""
local d_low = @min(date_1,date_2)
local d_hi = @max(date_1,date_2)
local d_1 = @timedom(d_low), m_1 = @timemoy(d_low) + 1, y_1 = @timey(d_low)
local d_2 = @timedom(d_hi), m_2 = @timemoy(d_hi) + 1, y_2 = @timey(d_hi)
local years_diff = y_2 - y_1
| if the higher date is earlier in a subsequent year reduce years_diff by 1
if @datesn(@str(d_2)+"."+@str(m_2)+"."+@str(y_1)) < d_low then years_diff-=1
local months_diff = (m_2 - m_1 + 12) % 12
| if the day of month for later date is higher than for earlier date,
| then the difference of days is a simple subtraction, but
| if the day of month for later date is lower than for earlier date,
| reduce the months_diff by 1, and find the number of days from the earlier
| date to end of that earlier month.
local days_diff = 0
if d_2 >= d_1
days_diff = d_2 - d_1 + inclusive
else
months_diff -= 1
local days_to_end_month = 0
if m_1 = 12 {December, must be 31 days}
days_to_end_of_month = 31 - d_1
else
days_to_end_of_month = @int(@datesn("1."+@str(m_1+1)+"."+@str(y_1)) -
d_low) - 1
endif
days_diff = d_2 + days_to_end_of_month + inclusive
endif
if years_diff then int_str = @str(years_diff) + "Y "
if months_diff then int_str += @str(months_diff) + "M "
return int_str + @str(days_diff) + "D"
enddef