Unanswered: Calculating difference between two ages
I need some advice with the following problem. I am setting up a database in Access which stores children's reading ages and calculates the difference between their reading age and chronological age. The inputs are the Reading Test Date, and the Reading Age. I have created a query which uses the DateDiff function to calculate the child's chronological age on the test date, but cannot work out how to calculate the difference between the reading age and the chronological age. The ages look like decimals, but of course they're not actually decimals, since 5.11 (for example) means 5 years and 11 months. So the difference between 5.11 and 6.2 would be 0.3 (no years and three months).
Any help / suggestions would be gratefully received!
Thanks for the suggestion. Actually, that was the first thing I tried but I was getting silly results with some (but not all) calculations. It may have been that my algorithm for doing the conversion into Years and Months was ropey so I'll give it another go. I agree the "decimal" notation I have used is presentation - I could have just as easily used 5 y 11 m or something similar.
That's pretty much the way I was converting ages in years/months to decimals. I did this for both ages (i.e. reading age and chronological age) then subtracted chron. age from reading age. So far so good. But reversing the calculation (i.e. multiplying by 12) to convert back to years/months gives, in some cases, stupid results. I'm clearly doing something wrong, probably something really obvious!