I sure wish they could figure out a way to calculate the number of Sundays after Pentecost that coincided with the number of the Propers in ordinary time. I know my readers who don't plan liturgies or are familiar with the Lectionary/Prayerbook have no earthly idea what I am talking about here.
For example, this coming Sunday is the 7th Sunday after Pentecost, but its Proper 10 in terms of the prayers and readings from the lectionary. I can always remember one but not the other, and have to look it up everytime to make sure the bulletin is right. I suppose this is what happens with having Easter as a floating Holy Day tied to the solstice and a lectionary/proper system that is on a fixed 12-month calendar.
What irritates me though is the fact that next year, it will be all different. Easter next year is extremely late, April 24th. It is very rare that Easter is after my birthday (April 21st). Thus, Pentecost falls on June 12th next year. Next year, the 7th Sunday after Pentecost will be July 31st making Proper 12 the correct readings and prayer for the day.
Ah well...thorns in the flest that irritate clergy that no one else really cares about.