Count Of Quarter Between Dates
You can also calculate how many quarters there is between current day and some date (here in A2 cell).
=FLOOR(((YEAR(NOW())-YEAR(A2))*12+MONTH(NOW())-MONTH(A2))/3;1)
Results are rounded down.
You might be interested also in date duration calculator.
Template
You can download the Template here – Download
Further reading: Basic concepts Getting started with Excel Cell References