Converting time to 'decimal'

I plan to use a javascript that is a little odd (?) about the time.

Is there a smart way off converting (item/)start to 'decimal'
In other words: 14:30 => 14.5

or is there another way to 'parse date time to javascript dates' ?

$('#timelineClock').timespace({
selectedEvent: -1,
data: {
events: [
{start: 6.25, end: 10, title: 'Walk', description: 'Go for a walk.'},
{start: 14.5, title: 'Lunch', description: 'Eat a healthy lunch.'},
{start: 14.75, title: 'Confirm Appointment', noDetails: true},
{start: 14.75, title: 'Bring Supplies'},
]
}

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