Forget about ISO 8601 and customary standards, let's use SI units.
Approximately 63 838 093.83 kiloseconds have passed since the beginning of the so-called "common era" in Greenwich.
I don't remember the time it was when I did this lol.
Basically, current date minus one and the time as is, times the average seconds for each.
I just used 0001 as the "beginning of the common era" just to simplify things lol.
Edit: I used 0001 as the "beginning of the common era."