This app in Avalonia 11.0.5 and .net 7 shows how much time has passed since a well-defined date that should represent an event, such as meeting a loved one, and shows how much time has passed since that date.

The use case is the song Life, death and miracles by Angelina Mango, and as you can see she easily explains everyday life in her songs, starting from the song 9 May which explains why she had to win friends.

In practice, a woman sees a handsome man and begins not to build castles in the air, those come later, but mental blowjobs.

The song goes "I see myself already posing, already dressed as a bride" and then continues "after days, after days I don't even remember your name".
A woman cares not about deadlines, but about anniversaries, this means that the date of meeting is important, not the date of the first time you make... love, but the date of the first meeting.
Then comes the name and surname and it is the same beautiful madam (read slut) par excellence who says "after days with you I don't even remember your name". So why not create software to write down the date of the meeting and the name, but not for two or three times, otherwise it's up to us, but for only one person at a time, perhaps accompanied by a button to delete the name and date if things don't go well.

This is female normality, women see handsome men on the street, they imagine themselves in a wedding dress but often they don't even remember their name, and they care about anniversaries.

This isn't mathematics but it's simple psychology, it means understanding the... beautiful artist, and understanding the... beautiful panorama, not cod or pes, but the fright!

It is not possible to insert a date after today's date, it gives an error.
It is possible to save today's date as a meeting date.
Shows whether it is the month anniversary or the anniversary.

Now there is a button to send happy birthday and anniversary wishes on Twitter.

Useful in managing relationships.
The name and date are saved in the settings, allowing for easy use of the app.