Acuity supports 2-way calendar syncing with iCloud.
2-way syncing adds appointments in Acuity Scheduling to your iCloud calendar and optionally blocks off time in Acuity from events on your calendar. To get connected and set things up, head to Business Settings > Sync with Other Calendar > iCloud.
Subscribe to your Acuity Scheduling calendar in iCal so that when new appointments are added to Acuity they will show up automatically in iCal.
Under Business Settings > Sync with Other Calendars > 1-Way Subscription and then click the button "Subscribe to Acuity ...". This will open up iCal and let you subscribe. iCal will periodically ask Acuity for updates to appointments, when you first subscribe you can choose how often it checks for updates.
When you get to the screen that looks like the image below change the "Auto-refresh" time to choose how frequently you'd like iCal to update. If you have multiple devices, like an iPad and an iPhone, change "Location" to iCloud
Changing how frequently iCal updates on your iPhone:
Just go into the "Settings" area on your phone, then into "Accounts & Passwords".
From there, go to "Fetch New Data", and you can have iCal check Acuity for new appointments automatically at a set interval (recommended, every 15 minutes) or manually (not recommended, you will need to refresh the calendar on your phone manually).
Removing 1-Way Subscription
If you're done using our 1-way Subscription, or switching to our 2-way syncing, you can remove the 1-way Subscription from your mac and your other devices.
In the Calendar app on your Mac, you can right click (or command click) on the subscription in your list of calendars. Then, simply choose delete and you'll be all set!
To remove the calendar subscription from your devices, head to Settings > Mail, Contacts, Calendars and select the account for the 1-way Acuity subscription. Then scroll down and tap Delete Account to remove the subscription.