Gigantt - When you estimate a task using free text you see a live preview of how the system is interpreting it.
/via Assaf Lavie
Harvest - When you leave a tab open on today’s timesheet and return to that tab the next day, it warns you that it’s a new day and provides a link to the new timesheet.
/via Mark van Lent
YouTube - When viewing a music video, it tells you where and when that artist is playing next in your area.
Pro Flowers - The date selector indicates the closer commemorative date in choosing the day for delivery.
/via Gabriel Henrique
Mac OSX - The world map displayed within the Data & Time system preference panel changes with the seasons.
/via John Blackburn
Google Images - When searching for some images which are somehow connected with recent events, it shows a little label with its age
Google - Google wishes you happy birthday based on the information from your Google+ profile. Clicking the doodle sends you to your profile at Google+.
/via Alexey Gornostaev
Google Calendar - Favicon displays the day of the month.