Auto create new columns

Hello,

I have a spreadsheet where I track attendance for my church throughout the year. We have events that happen on a daily basis. Most days I only have to track a single event but on Sundays I need to track Spanish Sunday School, Spanish Service, English Sunday School, and English Service attendance.

The spreadsheet is broken up into 12 months. Each month into 31 days, I use conditional formatting to hide any extra days in each month, and I have to rows with the day and the date.

The days are displayed with: =TEXT(DATE(CalendarYear,CalendarMonth,1),"aaa")

The date is displayed with: =TEXT(DATE(CalendarYear,CalendarMonth,1),"mm/dd/yy")

So of course "Sun" moves on the spreadsheet based on the date where it falls.

Is it possible to make it so that if the day = "Sun" that it creates the additional columns needed or perhaps have them hidden and they become visible if the day = "Sun"?

http://static.ccm2.net/ccm.net/pictures/uRJfDHXHr3gkS1ydq1v6QJuRqvHuLM2CsqXBjbnFwAkJcMiQJyaUSLK0v75kQ1Eg-days.png

here as an image of the spreadsheet.