Base36 time is simply the Unix timestamp, encoded in base 36 using lowercase alphanumeric digits.
The base36 timestamp is currently (1971 - 2038) six digits long. From smallest to largest, the digits count intervals of one second, 36 seconds, 21:36 minutes, 12:57:36 hours, 19.4 days, and 1.92 years respectively.
The format isn't very useful for communicating exact time, but its succinct timestamps are easier for humans to read, compare and pronounce.
For simplicity, this converter only supports dates with at most six digits. All decimal dates are shown in local time; the base36 timestamp is in UTC.