For Timing Conversions: It is nice to have it in minutes and secs and parts of secs, here is function in QB64:
_TITLE "Click and hold down on title bar to stop time!"
start## = TIMER
DO
CLS
LOCATE 1, 1
PRINT TIME$
LOCATE 2, 4: PRINT timePassed$(start##)
_DELAY .045
LOOP UNTIL theCowsComeHome
FUNCTION timePassed$ (started##)
IF started## > TIMER THEN started## = started## - 86400
tp## = TIMER - started##
t1$ = STR$(tp##)
dot = INSTR(t1$, ".")
t2$ = MID$(t1$, dot, 3)
t% = INT(tp##)
sec% = t% MOD 60
min% = INT(t% / 60) MOD 60
timePassed$ = STR$(min%) + ":" + RIGHT$(STR$(sec%), 2) + t2$
END FUNCTION