▁the ▁following ▁year ▁in ▁ 2 0 1 5 . ▁ ▁History ▁Even ▁before ▁World ▁War ▁II , ▁Har bor ▁Days ▁were ▁organized ▁to ▁advert ise ▁the ▁Port ▁of ▁Rot ter dam . ▁At ▁the ▁time , ▁these ▁were ▁one - day ▁events ▁organized ▁by ▁the ▁Rot ter dam ▁department ▁of ▁the ▁Dutch ▁company ▁for ▁industry ▁and ▁trade ▁and ▁the ▁board ▁of ▁the ▁H aven bel angen ▁Foundation . ▁The ▁target ▁group ▁was ▁not ▁the ▁general ▁public , ▁but ▁a ▁collection ▁of ▁prominent ▁domestic ▁and ▁foreign ▁business ▁relations . ▁The ▁first ▁Port ▁Day ▁was ▁held ▁on ▁September ▁ 1 2 , ▁ 1 9 3 5 ▁as ▁part ▁of ▁the ▁' V V V ▁week '. ▁The ▁program ▁included ▁a ▁boat ▁trip ▁through ▁the ▁ports , ▁a ▁l unch ▁in ▁the ▁former ▁officers ' ▁society ▁in ▁Het ▁Park ▁and ▁a ▁tea ▁in ▁the ▁Bo yman ▁Museum . ▁During ▁the ▁third ▁Har bor ▁Day ▁in ▁ 1 9 3 7 , ▁the ▁ 3 7 5 ▁guests ▁were ▁offered ▁l unch ▁in ▁the ▁civ ic ▁hall ▁of ▁the ▁town ▁hall , ▁after ▁which ▁they ▁took ▁a ▁cru ise ▁on ▁the ▁N ieu we ▁Water weg . ▁After ▁the ▁Second ▁World ▁War , ▁it ▁took ▁until ▁September ▁ 1 9 7 8 ▁when ▁the ▁organization ▁of ▁Rot ter dam ▁Mar itime ▁ 7 8 ▁brought ▁the ▁Har bor ▁Days ▁to ▁their ▁current ▁public - orient ed ▁character . ▁It ▁was ▁a ▁major ▁event ▁with ▁a ▁fleet ▁show ▁on ▁the ▁N ieu we ▁Ma as ▁with