format
Return the given time in a human-readable format, such as "0:10" or "01:23:45".
If the time is infinite or NaN, this returns "--:--".
Parameters
time
the time (in seconds) to be formatted
guide
another time (in seconds) such that the returned formatted time has the same number of parts and number of leading zeros as this guide.
prefer
whether the returned formatted time should preferably be negative, for example because it represents the time remaining in the video.