The time keeping system I've been taught and use has the following (cumbersome) units:
Months, Days of the month, hours of the day, minutes of the hour, and seconds of the minute... above and below these units base 10 units are used (e.g. years and milliseconds)
I realize that the awkward calendar units are intended to align the year with the seasons, and the irregular clock units were "designed" for the convenience of dividing the hour (e.g. 1/2 hour, 1/4 hour, 1/5 hour, 1/6 hour) but these days it would seem that a reasonable approach would be Metric Time (e.g. base 10 for all units)...
Is/was any such system ever proposed... or in use? If so, how does it work?