We use SharePoint in my company, our root site have company calendar and we have departmental SharePoint site, each of it contains their own departmental calendar. Our requirement is that in each department sites I need a web part which shows the global and departmental calendar events in one web part, and in root site I need to show all calendar including the root calendar in a web part.

Here am presenting my Globalized Calendar Web part v1.0

I will keep updating how I did this and the theory behind this and even source code later. Now am attaching the ".wsp" - GlobalCalendar.wsp (11.08 kb)