A question about changing npc equips on set time

Hello there TC,
I have a question about the conditions system and its capabilities.
I am not sure if what I am trying to do will need to be coded in C++ or can be handled in Conditions or even the event system.
In current retail servers once night is triggered if you go to say Stormwind Some guards are holding lanterns.
But when you come back when day is triggered they have their weapons equipped

Is there a way to handle this either by conditions or events system or is this something that I will have to code in C++ to handle?

I have an other question also.

Does anyone know how the sound is called to client for on the hour chimes in capital cities? IE drums in Orgrimmar or Bells In Stormwind

Any suggestions on either question is greatly appreciated.
Thank you for your time