Prior instances when it was on April 22 (non-leap years)
and April 21 (leap years).
I take LEAP YEARS into account.
I count days from January 1, taking into account leap years.
So, April 21 & April 22 are 111-days in From Jan. 1
depending on whether it was Leap Year or not.
Prevailing consensus is that it most likely will be April 22 in 2019. But, there could always be a pesky little floe floating around that could delay it by 12-, 24-, 36 or even 48-hours.
I am just going with the flow.
Search ‘Winni‘ & ‘ice‘.