There is nothing “ordinary” about “Ordinary Time”. Ordinary Time is not about common, regular, mundane, or run of the mill. Ordinary Time comes from the word “ordinal” as in “ordinal numbers”. Remember your Maths: Cardinal numbers answer “how many?” “Ordinal Numbers” tell the rank, they answer “what position?” Ordinal Numbers are first, second, third, fourth, etc.
There are normally fifty-two weeks in a year. These are made up of the Advent, Christmas, Lent, and Easter Seasons. Normally that leaves thirty-four weeks of “Ordinary Time”. Those weeks start from The Baptism of the Lord up to Lent, and start again at the Day of Pentecost.
[Complicated bit: Ordinary weeks count forward from The Baptism of the Lord. After the Day of Pentecost, however, they are checked backwards from the last week of the Church’s Year which is always the 34th week of Ordinary Time. So sometimes a week is dropped out – as in 2015. End of complicated bit.]
The week before Lent in 2015 was the sixth week in Ordinary Time. The week following the Day of Pentecost is the eighth week in Ordinary Time. The following week (following Trinity Sunday) is the ninth week in Ordinary Time. And, lo and behold, the Sunday after that is the 10th Ordinary Sunday (actually the Sunday in the 10th week of Ordinary Time).
[Complicated bit: the Sunday after Trinity Sunday is often celebrated as Corpus Christi, and in our church as Te Pouhere Sunday. The Baptism of the Lord, the Day of Pentecost, Trinity Sunday always replace the “Ordinary Sunday”, other “bold letter” Sundays might also. Each Ordinary Sunday is limited to a particular week in the year. Eg. the 5th Ordinary Sunday is always the Sunday between 4 February and 10 February, the 11th Ordinary Sunday is always the Sunday between 12 and 18 June. End of complicated bit.]
May your Ordinary Time be extraordinary!