How do I change my wifi cycle in moto g? I had the same problem with data usage but that got solved. The drop down button in the wifi tab does not have the change cycle option. Please help with that.
The drop down button in the wifi tab does not have the change cycle
  option


That is very much expected. The data usage and monthly billing cycle of internet that you are using through Wi-Fi is provided via Router and is not controlled through Mobile device.

Since SIM-based Mobile internet is very much tied to the mobile itself, Android provides Setting to adjust the billing cycle to view/control data usage. 

So, you cannot control your Wi-Fi Cycle via Android Settings. You may need to connect with your Internet Service Provider to check for change in Wi-Fi Billing cycle.