clock.lua

local monitor = peripheral.find('monitor')

function getFormattedTime()
    local now = os.time()
    local hour = math.floor(now)
    local minute = math.floor(now * 60) % 60
    -- local second = math.floor(now * 60 * 60) % 60
    return ("%02d:%02d"):format(hour, minute)
end

function canSleep()
    local now = os.time()
    local tick = math.floor(((now + (24 - 6)) % 24) * 1000)
    -- print(tick)
    return 12542 <= tick and tick < 23460
end

function setup()
    monitor.setTextScale(1)
end

function setColor()
    if canSleep() then
        monitor.setTextColor(colors.white)
        monitor.setBackgroundColor(colors.black)
    else
        monitor.setTextColor(colors.black)
        monitor.setBackgroundColor(colors.white)
    end
end

function update()
    setColor()

    monitor.clear()
    monitor.setCursorPos(2, 3)
    monitor.write(getFormattedTime())
end

setup()

while true do
    update()
    os.sleep()
end