My solution attached.
Step 1) extract the year using formula
tonumber(right([Date], 4))
Step 2) extract the month using formula
tonumber(replace(left([Date], 2), "/", ""))
Step 3) extract the quarter using formula
if [Month] in (1, 2, 3) then "Q1"
elseif [Month] in (4, 5, 6) then "Q2"
elseif [Month] in (7, 8, 9) then "Q3"
elseif [Month] in (10, 11, 12) then "Q4"
else "" endif
Step 4) concatenate the year and quarter using formula
tostring([Year]) + tostring([Quarter])
Easy problem since all dates are cleanly formatted. Unfortunately in the real world this is not always the case.
