I am looking at organizing a small conference next summer and I would like by all means to avoid concurrent dates with any major or highly-overlapping conference on the same or related topics. I thought that it would be really useful if there was an online directory where I can check a calendar of upcoming scientific conferences and workshops (maybe sorted by field) and plan mine on a week in which it does not coincide with an already planned event. That way I would not be "competing" for speakers and attendants against the organizer of a different event. I would prefer to avoid "manually" browsing the internet to find this information out, so a centralized online service would be perfect for my needs.
Does such an online resource exist? If the answer depends on the discipline, I am mostly interested in physics, chemistry and materials science conferences and workshops.