As a Catholic, important celebrations are always octaves (8 days!) so I generally would celebrate a birthday octave anyway! (I used to have a housemate who always did so, and it rubbed off!) At WDW, I wore my birthday badge for maybe three days, as after that I was ready not to have people wish me Happy Birthday all the time!
We arrived on our trip this time on our anniversary, and wore those badge for the first 2/3 days too. As the new badges don't specify anniversary/wedding/etc, we had one CM ask if we were on our honeymoon (awww, thanks but no- 6 years married!) and otherwise they ignored it in a way that didn't happy two years ago when we had the specific anniversary badge.