In Japan, the new era will start on May 1, new imperial era name is "Reiwa" (Japanese: れいわ), which is remains significant to most Japanese in their daily life, it affects various economic activities.
In Japan, the date on the general business documents including the trademark registration certificate will indicate the imperial era name.
This is different from each A.D new year replacement, because the year to the new year is made up of numbers, it is foreseeable, knowing the years after hundreds, thousands or even tens of thousands of years, the Japanese imperial era name is studied by government experts and is not announced in advance.
Of course, this does not affect any trademark application. The change of the imperial era name is only a change of the future date. It is just as normal as the change of the year of the year such as 2019 to 2020.