In 2017, I invented a logarithmic calendar/"age" measurement based on the idea that the rate at which time seems to pass, in terms of important life events, is directly proportional to the amount of time we've already lived, an idea that I first heard about in a Vsauce video.
Of course, this means that one's birth "feels" like an infinitely long time before the present. So I needed to set an arbitrary time in one's life to be the "zero" in this system. I decided to make "zero" coincide with my thirteenth birthday in 2012, because the year 2012 was a legendary time and a turning point in my life in many ways.
The "units" of this system are "perceived years at 13." A perceived year at 13 is defined as an interval of time that feels as long as an average year would feel under the time perception I had on my 13th birthday. An "average year" is defined as 1/13 the time between my birth and my 13th birthday, for ease of calculation. This is slightly different from the mean year in the Julian or Gregorian calendars, or the mean solar year.
Your logarithmic age in "perceived years at 13" since you were 13:
Note: So far, there's no way to enter the time of day you were born, so the counter uses the beginning of the day in your local timezone. This makes the count slightly inaccurate, but revealing the time of day I was born is just a little too personal for this site.