Orient ER2L004W
Multi-year calendar, 2015 through 2056
The crown at 2 o'clock rotates the year/day under-dial. Align the year and month to set the calendar. Leap years (like 2016) are printed white on black. January and February are duplicated, black on white and white on black: the white on black months are used to set January and February in leap years. The calendar in the photograph is set for May 2016.
This is an update of the original Orient from 1960. They were popular novelty watches. Wittnauer sold rebranded Orients in the USA. There were lots of copies, notably Raketa and Luch.
In 1983, Orient modified their original design.
The windows for the under-dial moved inboard of the calendars, and the crown at 2 o'clock was replaced by a button you can't see in my photograph. One drawback of the original design is that the 2 o'clock crown does not lock, and it is easy to bump it with the back of your hand and move the calendar. Orient replaced that crown with a button you can't see in my photo. Orient used a 2 o'clock button to set the day on its Mako and TriStar watches, so that was an easy substitution. Once set, the calendar would stay set, but setting it became a tedious chore. LOTS of button pushing and it was one way only: go past where you want and you have to go all the way around to get back. IMO the first pattern was superior, and that was what everyone imitated.

