Counting items based on criteria located in multiple columns

Hi

I'm working on a dataset which contains 'Date' and 'Type' of audits.

I need to count across the range, for number of instances where:
1. The 'Date is between 1st Jan 2018 and 1st April 2018' and
2. Type is 'S'.

There may be situations where I need to insert column between D&Q. SO, the formula should automatically adjust for the column insertion.

1.png