Synonyms to on what occasion

when, after all, again, albeit, all the same, although, anon, as far as, as long as, at all events, at any rate, at what time, at which, at which time, but, during which time, even, even so, for all that, howbeit, however, in any case, in any event, in what period, in which time, just the same, nevertheless, nonetheless, notwithstanding, on which occasion, rather, still, the while, though, upon which, what time, when as, whenever, whereas, whereupon, while, whilst, yet, anytime, at any time, at whatever time, if ever, no matter when, once, whensoever, after which, hereinafter, on, upon, whereat, wherefore, whereon, whereto, whereunto, wherewith