is iOS11/iOS12 supported?

The update was being worked on, but due to lack of time and resources it was put on hold. It is not known when/if work on the update will resume.

I would like to be notified of upcoming events without going into the program - can I do this?

Yes. There are several notification options including what types of events to display as alerts, the alert sound, alert time, show tomorrows events, and show badge count. These can be selected in Holiday Countdown's settings.

Does this app support iOS7 and the taller screen of the iPhone 5s?

Yes, Holiday countdown is optimized for iOS7 and takes advantage of the larger screen.

What are the latest features?

Now you can optionally see just the number of weekdays until an event.

Is there integration with the device's built-in calendar?

Yes, you can import and export using the built-in device calendar. You can also select calendars used for import/export.

What is the difference between importing birthdays with the option "Only add new" compared to "Overwrite existing"?

When importing birthdays from your contacts automatically, the first and last name of each of your contacts that have a birthday entry will be combined with the word "Bday" and this will form the name of the new custom event (Such as "John Smith Bday").

When selecting "Only add new" if a previous entry with the birthday name has already been created, it will not be touched in any way. If you select "Overwrite existing" then not only will it add new birthday events, but also update the dates of any existing events where the birthday or note has been changed in your contacts. You will receive a pop-up alert describing how many birthday events were added and updated.

The color of the imported birthdays is set to your default color. The icon used is the symbol of balloons. You can change the color or icon on an individual basis.