/f{print dup 9 le{(0)print}if =only}def[.runstdin]{dup 31556926 idiv
0(\3\3\4\5\6\7\b\t\n\13\f\r\17\21\24\24\26\30\30\32\33\35$){2 index le{1
add}if}forall exch pop sub 86400 2 copy idiv dup 0.26 sub 365.25 div cvi dup
1970 add dup =only 3 1 roll 365.25 mul 0.26 add cvi sub 1 add 1
exch(\37\34\37\36\37\36\37\37\36\37\36\37)dup 1 28 6 index 4 mod 0 eq{1 add}if
put{2 copy le{pop exit}if sub exch 1 add exch}forall exch(-)f(-)f pop mod
2{dup 60 mod exch 60 idiv}repeat( )f(:)f(:)f()=}forall
Note that non-ascii characters in the above source code will be escaped (such as \x9f).