Help with CASE WHEN date is >= 90

I am trying to do a CASE WHEN (first time) and I am having the error field not found. This is in a saved search. I think my error might be in the packedDate or transDate comparing to 90. Would really love any help here as this is my first delve into SQL. Thanks

CASE

WHEN {quantityBackOrdered} IS NULL THEN '<div style="color:black;background-color:yellow;padding:5px;text-align:center;border-radius: 25px;">' || '☆ No Back Order' || '</div>'

WHEN {packedDate} >= 90 THEN '<div style="color:black;background-color:blue;padding:5px;text-align:center;border-radius: 25px;">' || '☆ No Pack' || '</div>'

WHEN {tranDate} >= 90 THEN '<div style="color:black;background-color:red;padding:5px;text-align:center;border-radius: 25px;">' || '☆ No Trans' || '</div>'

WHEN {packedDate} >= 90 AND {tranDate} >= 90 THEN '<div style="color:black;background-color:#C2A887;padding:5px;text-align:center;border-radius: 25px;">' || '☆ DUSTY' || '</div>'

ELSE '<div style="color:white;background-color:green;padding:5px;text-align:center;border-radius: 25px">' || '★ Great'

END

Would really love any help here as this is my first delve into SQL. Thanks