How do you match your week numbering with your lot numbers

We have recently added an option to our Lot Algorithms that places the week number into the lot no. based on a given date.
Recently, we had a discussion with one of our customers as they had logged an issue that the week number that we used was incorrect and was “off by 1”.

Our customer was using MS Outlook calendar to test this. They looked at their calendar and it showed them that March 18 falls in week 12, however when our routine calculated the lot no. for March 18, it assigned the lot no. week 11 (see…..off by 1).

There is a standard (ISO 1861) way of determining the week number and there is the default Microsoft Outlook way. Microsoft Dynamics NAV uses the standard when determining the week number.

As per the standard, week 1 is defined as:
• the week with the year's first Thursday in it (the formal ISO definition),
• the week with 4 January in it,
• the first week with the majority (four or more) of its days in the starting year, and
• the week starting with the Monday in the period 29 December – 4 January.
Because January 1, 2010 was a Friday, you would be off by 1 week based on the standard if you counted January 1 as week 1.

So, the reason Outlook was “wrong” was because it’s default setting is in fact to count January 1 as week 1. This can be changed in your Outlook settings shown below. The option of “First 4-day week” would be the correct option to have it align with the way NAV calculates the week numbering.

Calendar settings in Outlook:

Mike is the Chief Architect of JustFoodERP. He has over 10 years experience in software development working specifically for technology companies. He leads the development team at JustFoodERP. He is accountable for JustFoodERP’s product quality, design architecture, and the future product path. When he’s not thinking about software he is running around crazily with his four kids and squeezing a few minutes for gaming and playing the guitar.