I can understand making the March edition available in February to allow time for distribution, but April? 

ISO 3103 compliant
It's sad fact that selling the March issue in March and the April issue in April costs sales as buyers select the 'latest' magazine from competitors. Of course subscribing means that you're always one of the first to get the latest issue, it means that you get it delivered to your door, and it means that you pay a lot less than you would on the newsstand 
Ian

Ian
Twitter & Instagram @iancseager
My May issue arrived by post on 29th March....
Pete S as was
Pungens ego nimis inflatorum
Pungens ego nimis inflatorum

The June issue arrived last week.
While you might think that I couldn't possibly comment.