I need to give my cat medication every 2 days around 6PM
Is the best way to setup a RM4 where the trigger is Periodic Schedule? Still trying to figure out how to start the trigger other than remove the pause on a medication day and let it run.
Unfortunately, that's not going to work the way you want. Periodic uses Cron, and Cron is peculiar. That will give you every other day within a month, but not alternating days. So for this month it would give you 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, and then August 1, 3, etc.
Seems to me you could use a Private Boolean within the Rule that gets toggled every day at 6pm. Only if it is true, speak the Notification. The days it is false there would be no notification.
If you don't mind using the cloud, Use IFTTT and have it trigger when an event starts in Google Calendar, then flip a switch on for 1 second in HE to give the notification on your Echo.
Then just put the event for every other day at 6PM in your google calendar linked to the IFTTT account.