A bill cycle is the start and end date of your bill and usually is between one and three months.
With AGL, you can choose to be billed monthly and help keep your bills down. For non-smart meter customers on monthly billing, up to two out of every three bills can be based on an estimate of your usage, taking into consideration your usage history and seasonal data. You can avoid this by submitting a self-service meter read in My Account or the AGL Energy app around the end of your bill cycle.
Quarterly or bi-monthly bills are higher because they're based off actual meter reads and come every two-three months.
The bill cycle date is the date in the month or quarter that your bill is generated and sent to you. For example, your bill might be generated on the 15th of the month.
View or change your bill frequency in My Account by going to Account Settings > Billing and Payments > Bill Frequency. If you're using the AGL Energy app, you can change your billing frequency by going to the Account tab, selecting Settings then Monthly Billing.