Easy one: WF: Minutes to sleep doesn't work

Since sleepTime is expressed in terms of seconds past local midnight, you can determine the current time in terms of seconds past local midnight and compare the two values. Then you can do whatever you want with the result, including converting it to minutes and formatting it for display.

(The docs for Time, Moment and Duration are helpful in this case)

e.g.

// Returns:
// - null if the sleep time is unavailable
// - The number of seconds until today's sleep time:
//   >= 0 if the sleep time is now or in the future
//   < 0 if the sleep time is in the past
function secondsToSleep() {
    var userProfile = UserProfile.getProfile();
    if (userProfile.sleepTime == null) {
        return null;
    }

    // get a Moment for the current time
    var now = Time.now();
    // get a Moment for midnight today (the beginning of the current day)
    var today = Time.today();
    // current time (in seconds past midnight) = now - today
    var currentSecondsPastMidnight = now.compare(today);

    return userProfile.sleepTime.value() - currentSecondsPastMidnight;
}

Note that this function returns a negative number if the current time is already past today's sleep time. e.g. If the your sleep time is 10:00 PM (22:00) and the current time is 10:01 PM (22:01), then this function will return -60. It can easily be tweaked to return the time until *tomorrow's* sleep time in this case: if the result is negative, add one day's worth of seconds (24 * 60 * 60) to the result.