I think this is, happily -- nay, wonderfully! -- an area where there's room for Gloranthans to disagree, and for those disagreements to be very much like those of the Gloranfans in this thread. People would likely agree in general terms that there's a somewhat jumbled quality to the God Time as one experiences it through myth, ritual, and HeroQuest. The Orlanthi, and anyone else buying into the "Year 1: Sun Rises" premise, will see that as an inherent thing -- if anything, as Charles says, any apparent linearity is something of an imposition by the observers, and the "deep reality" is even more thus.
Those cultures with extensive, detailed (and needless to say, mutually contradictory) calendars back to the Green Age think the reverse: they actually happened in a strict temporal order, and the jumbly nature of the magical effects are due to the sad, sad state of things in the modern day world. Accumulated errors in storytelling, and the malign influence of foreign, degenerative forces in the Otherworld. But it's nothing that clean living, a return to traditional values, and some vigorously corrective HeroQuesting won't prolo-- eh, I mean cure!