That's right, Bob. Measurement starts at zero, counting starts with 1. The clock starts at zero. After 24 hours, 1 day has passed. Day 1 has passed. Day 2 has started. That's whay the last year of the first decade was year 10, the last year of the first century was year 100, and the last year of the first millennium was year 1000. The second millennium started at the beginning of year 1001 and runs through the end of year 2000.

Your age is a measurement, the calendar is a system of counting. Someone keeps trying to say days are counted but years are measured, because Christ was born. I don't buy it.