pad hours and minutes with zero

vibrating_alarm_m5stickc.py

@@ -25,7 +25,9 @@ clock_update_timer = machine.Timer(0)
 clock_update_timer.init(
     period=10000,  # ms
     mode=machine.Timer.PERIODIC,
-    callback=lambda t: clock_text_box.setText("{}:{}".format(*rtc.datetime()[4:6])),
+    callback=lambda t: clock_text_box.setText(
+        "{:02d}:{:02d}".format(*rtc.datetime()[4:6])
+    ),
 )
 
 # TODO https://docs.micropython.org/en/latest/library/machine.WDT.html#machine-wdt