clock

local updateRate = 0.08
local updateTimer = os.startTimer(updateRate)
local offsetX,offsetY=0,0
local autoCenter = false
local monSide = "top"
local monScale = nil
local writeTerm = term

if monSide then
  writeTerm = peripheral.wrap(monSide)
  if monScale then
    writeTerm.setTextScale(monScale)
  end
end

if autoCenter then
  local w = writeTerm.getSize()
  offsetX = math.ceil(w/2) - 4 - 1
end

while true do
  local ev, uTimer = os.pullEvent("timer")
  if updateTimer == uTimer then
    writeTerm.setCursorPos(1+offsetX,1+offsetY)
    writeTerm.clearLine()
    local time = os.time()
    local hours = math.floor(time)
    local minutes = math.floor( (time - hours)*60)
    local ampm = "am"

    if hours > 11 then
      ampm = "pm"
      if hours > 12 then
        hours = hours - 12
      end
    elseif hours == 0 then hours = 12
    end
    writeTerm.write(string.format("%s:%s",(hours<10 and "0"..hours or hours),(minutes<10 and "0"..minutes or minutes)).. " " .. ampm)
    updateTimer = os.startTimer(updateRate)
  end
end