TestTime

timeOfDay = "Day"
os.loadAPI("ocs/apis/sensor")
mySensor = sensor.wrap("top")

currentMinutes = -1
currentSeconds = -1

function printTime(minutes, seconds)
    currentSeconds = seconds
    currentMinutes = minutes
    min = tostring(minutes)
    sec = tostring(seconds)
    if string.len(sec) == 1 then
        sec = "0"..sec
    end
    if timeOfDay == "Day" then
        term.clear()
        term.setCursorPos(1,1)
        print(min..":"..sec.." till Night")
    else
        term.clear()
        term.setCursorPos(1,1)
        print(min..":"..sec.." till Day")
    end
end

function getTime()
    returnedString = textutils.serialize(mySensor.getTargets())
    angleIdx = string.find(returnedString, "Angle") + 8
    timeRatio = tonumber(string.sub(string.sub(returnedString,angleIdx), 1, -5))
    if timeRatio >= .5 then
        timeRatio = timeRatio - .5
        timeOfDay = "Night"
    else
        timeOfDay = "Day"
    end
    time = 10 - 2 * (10 * timeRatio)
    minutes = math.floor(time)
    secondsDecimal = time - minutes
    seconds = math.floor(secondsDecimal * 60)
    if (seconds ~= currentSeconds or minutes ~= currentMinutes) then
        printTime(minutes, seconds)
    end
end

function run()
    while true do
        getTime()
    end
end

run()