Appears to me to be a 1969 Time Center "A" based on on-site research; as referenced in the shown 1969 ad. Watch movement has an interesting clear lucite spacer pressed into the back that I have never encountered. Case and movement both dated M9. Band is a period replacement with 1973 dated calendar spool in it. I would assume the original had a spool that was generic with a selection of months starting the first of the month on each day of the week so it would be good "forever".
Interesting note: the face shows an incorrect "IIII" for the number 4 instead of "IV".One would assume that was artistic license to balance the face. Personally I think it would have been better balanced if all numerals below the 9 - 3 line were composed if "I's" and "V's" and all above being "I's" and "X's".