I have data numbered 1 to 12 for months and 1 to 52 for weeks, and I am using Monthname and Weekname to convert it into Month and Weeks. However when doing so Week 40 2012 returns Oct 2012. See below script for example.
Yes, after some further testing this was also my conclusion, and eventhough the make date of week 40 is made for 6th day of the week, the Weekname function transfers it into the same timestamp as the month. My first assumption was that it would only convert the part where the classification was true, but as soon as the timestamp have been converted,it sticks eventhough the same timestamp may appear as week as well.
Solution was to make a text representation as well, a bit more complex but it works.