Антонимом so today

tomorrow morrow the consequent day the following day the next day the subsequent day

yesterday yore yesteryear history foretime auld lang syne lang syne the last Day the other day the past the previous day

then before previously formerly long once at one point at one time at that instant in days gone by in days of yore in the old days in the olden days in the past in those days in times gone by in times past long ago earlier antecedently up till now in years gone by in former times at an earlier time

tomorrow morrow

yesterday

obsolete out of date ancient antiquated archaic outdated outmoded extinct obscure old dated defunct deprecated obsolescent outworn passé prehistoric stale superannuated superseded unfashionable antediluvian antique bygone dead discarded discontinued disused geriatric gone mediaeval medieval moribund neolithic old-fashioned old-school out of fashion dusty elapsed expired has-been invalid lapsed musty out-of-date out-of-fashion prehistorical timeworn void done for mouldy moldy past it rusty behind the times dead and gone fallen into disuse had it kaput no longer in use old-time oldfangled fusty past

asynchronous noncontemporary nonsimultaneous nonsynchronous diachronic

sotted sottish sottishly sottishness sotto voce soubriquet so this sot so-so so so SOS sort things out