Subject: RE: Calculate diffrence between dates - weeks - but not so simple ... From: "Monnier, Gary" Date: Thu, 7 Apr 2011 12:20:39 -0400 List-archive: List-help: List-id: Midrange Systems Technical Discussion List-post: List-subscribe: , List-unsubscribe: ,

Tomek,

I think you can accomplish what you want with the ILE CEE date and time
APIs.

Basic steps are:

1. Convert your non-Lilian dates to Lilian dates (CEEDAYS API)

2. Subtract your ending Lilian date from your starting Lilian date.
This will give you the number of days between the two dates.

3. If the difference is > 7 divide by 2 to determine the number of
weeks.

You may need to do some offset work based on your Saturday being the
first day of the week requirement. The CEEDYWK API will give you a
numerical representation for a day of the week.

1 7 Sunday

2 3 Monday

3 4 Tuesday

4 5 Wednesday

5 6 Thursday

6 7 Friday

7 1 Saturday

Gary

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Tomasz Skorza
Sent: Thursday, April 07, 2011 6:58 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Calculate diffrence between dates - weeks - but not so simple
...

Hi

I need to create an algorithm which allow me to calculate diffrence
between two dates but assumption

is that first day of week is SATURDAY, and week going from saturday to
friday.

So if first date is 2011-03-28 - monday, then for second date from
2011-03-29 to 2011-04-01

algorithm should return 1 (week), but for 2011-04-02 - saturday
algorithm should return 2 (weeks).

Have you any idea?

I tried many posssibilities and something is wrong, depend on start and
stop dates sometimes result

is as I expect sometimes not ...

Regards

Tomek