However, the date for 2015 is only one week after the Solar eclipse on 20.03. and the Astronomy Day on the 21.03. and is hence somewhat challenging for the contributing astronomers. As most visitors of the astronomy day are already interested in astronomy to at least some extend, these differ from the majority of people who are targeted by the sidewalk astronomy actions. The latter mostly people who are not yet active in astronomy. Especially for those persons whose interest in astronomy is activated by the ISAN, the opposite arrangement of dates would be preferable. In that case, the ISAN would be some sort of advertising for the much more coordinated events of the astronomy day in Germany, Austria, Switzerland and some bordering countries and, at least this year, for the solar eclipse on the 20.03.. This, however, is not possible for 2015 any more.
Although it is not ideal to split an international activity on different dates for different parts of the world, it might be good to consider having a different date for Europe and the Americas. In my opinion, a separate, later date for Europe would be preferable. Probably on a Saturday before the Lunar eclipse on the 28. September 2015? I would love to read more comments on that topic in the comment section!