Interactive publication
Back to the catalogueWeek systemsCase 04 of 08
Competing week-numbering systems
ISO weeks start Monday; US/retail weeks often start Sunday; broadcast (Nielsen) weeks start Monday but sit inside a different month calendar; some Middle-Eastern weeks start Saturday or Sunday. 'Week 29' is ambiguous without the system.
Class
Case to account for
Affects
1 conversion
01
Detection
A week number arrives without its numbering system declared.
02
Mitigation
01
Declare the week system; default to ISO-8601; provide crosswalks to US/broadcast.
03
Affected conversions
Instant(ISO week × slot) key
OPEN