I don't know sure sure with the info you gave.
First character is the month, second is the year.
This started in 1965. AA would be Jan 65, BA Feb 65, CA March 65, AB Jan 66, BB Feb 66, CB March 66, AD Jan 68, AE Jan 69, etc.
The 2 letters that are skipped is I and O because they too close to numerals, so May 73 would be EJ, June 73 FJ, etc. I know this system was used till 1980, not sure after that.
Assuming this code was still in use after 1980, E is May,W is 1985. The thing that is odd, serial number is on bottom bracket like a pre-1952, not on the head tube like a post-1969. Maybe location changed sometime after 1980 since serial numbers with 2 letters started in 1965.
Before 1965 was different and sometimes you need a date chart to find out.
If it was was May 1959, the serial # would be E9xxxxx, not EWxxxxxx.
It helps to date them by looking at the bikes characteristics, paint, style, model name, etc. And it is possible it is pre-1948 where seiail numbers have been lost.
Need more info or pics.
What does the frame's paint look like.
Trivia, the date code that started in 1965, Chrysler started using the same code for car parts in 1965.