An Etymological Dictionary of the German Language/gestern

by Friedrich Kluge

gestern, adv., ‘yesterday,’ from the equiv. MidHG. gëstern (gëster), OHG. gëstaron (gëstre), adv.; also, with a divergent meaning, OHG. êgëstern, ‘the day after to-morrow’ (and ‘the day before yesterday’); corresponding to Goth. gistradagis, ‘to-morrow,’ OIc. ìgœr, ‘to-morrow, yesterday.’ It is evident that the primary word was used in the double sense of ‘to-morrow’ and ‘yesterday’ (lit. ‘on the second day from this’); comp. also AS. geostra, gistrandœg, E. yesterday, Du. gisteren, ‘yesterday.’ The form and the idea are Aryan; comp. Sans. hyás, ‘yesterday,’ Gr. χθές, Lat. heri (for hjiesi?); ghyés is the primit. form, whence with the suffix tro-, ghistro-, ghyestro- (Goth. gistra). For heute, ‘to-day,’ and morgen, ‘to-morrow’ (Lat. cras, Sans. çrás), an equally diffused form is wanting.