This is not like the Holiday called "Day of the
dead" nor is this a Death Date which is an archive to remember the date / anniversery of someone's death.
A Deathday is the day you will
die. It's your personal scheduled "momento mori".
For
people suffering dpression or other mental illneses who plan to kill themselves if their life doesn't improve by then. Or if they feel like they've gain the confidence to perservere.
They know that setting a Deathday is the moment they will
die. Those who set deathdays are self-aware that they'll
die just to fix a temporary life struggle but feel overwhelmed by their circumstances. If you know anyone with a deathday on their calender and it's closely approaching, urge them to seek professional
help.