I am designing a calendar icon for an app, I am putting a random date right now on it, what should be ideal date that I should put. Is there any usability research done on the same? I know the best scenario can be if it can display the current date, but right now it might be too much an overkill to develop such a feature, so what should be the ideal date that i should put on the icon? Blackberry puts it to be 31, another number which I though was quite eye catchy was 23. Is there any such paradigm that a particular date is catchier?
Try doing a google search on calendar icon and then you capture the results (if worth it). Just by skimming the results I saw that 9 was a popular number, but not far from others.
From the Semiotics perspective 31 might work, as people easily identify it as the maximum number of days a month can get, and design-wise is filling.
I think that only having the red bar at the top and a big bold black number (or calendar grid (SMTWXFS) id size permits) at the bottom is good enough for people to identify the icon.
If it is technically feasible, update the icon on an hourly/daily base to show the current date/day. This way, the user sees the current date/day by just browsing through the set of application icons without starting the calendar application.
Technically, it may require configuring and running a system service to redraw the icon at midnight without user interaction.