I am worrying.... may someone kindly help me..

I came to know the other day thru a book, it says 4:33 comes from minus 273
degrees(absolute zero degree in temperature), i.e.  273 seconds = 4minute
and 33 seconds

However, why he didnt take it as 273 hours or 273 milliseconds...  or
273 days  273years if you like,  long and eternal life...

I am worrying...

N.Inoue