App: TimeTill for Calendar
Developer: Golmium
Genres: Utilities, Lifestyle

From Mac Softpedia review (http://mac.softpedia.com/get/Utilities/TimeTill.shtml): 

"TimeTill is a small yet efficient application that brings all the information in the same user interface, allows you to filter the entries by calendar or importance, and lets you know how much time is left until each event."

The app displays your Calendar's events and Reminders' items in one sorted by time list.

You see them all at one glance with calculated countdown times.

Features:

- Time in various formats and units

- See only calendar events or only reminders items or both

- Filtering by individual calendars 

- Search for events and items by descriptions

- Optionally use calendars colors   

- Select important items to follow them up in an emphasized view   


Strictly business: neither fancy user interface nor distracting graphics is between you and your data.

For performance reasons,  the timespan of future and the timespan of past events are both limited to four years.

The iPad / iPhone version is also available.

Release notes:
- 'Since' list ordering made optionally from recent to old or from old to recent
- Added ability to space the lines a little further apart
- Resolved issue with too often requests for rating/review 
- Other minor problems fixed