Observatory is a place to search for interesting details based on custom criteria. Set the date of interest and see what it looked like and what elements were captured in it. Here it is also possible to see how many times a certain tag is present on the photo and browse through the days when it appears. You can set several tags and see how many photographs contain this selection. For example, on how many days pancake boat and sea liner where seen together, or explore if there is a relation between rainy days and the amount of pleasure boats.