I tried a new corn variety last year called Damaum. This is a fairly recent breeding from Europe which is open pollinated and therefore any seed that you saved would breed true. Cobs will be ready about 95 days after sowing which means a Mid April sowing will be ready from the beginning of August and successional sowings can take you to the first frosts in October.
I remember watching a gardening program in the 80’s where the presenter was emphasising the speed at which you needed to cook sweetcorn from the moment it was picked as the sugars started to turn to starch. In those days the only way to taste good sweet corn was to grow your own. Sweetcorn breeding has come a long way since then with the development of the tender sweet and then super sweet varieties, both of which are much sweeter and also have a longer shelf life which means no more running from plot to plate!