This research note looks at the development of an electoral gender gap over time, using, for the first time, actual ballot data collected in the Austrian state of Vienna. Vienna recorded female and male ballots separately in the years from 1954 to 1991. Firstly, using this unique design, we conclude that the traditional gender gap (males more left-leaning) existed up to 1969 and then changed into the modern gender gap (females more left-leaning), from that date. These results confirm the considerable literature based on survey data. As an alternative explanation for the observed patter we explore, the gender gap in voting for the central vs the flank parties. We can confirm survey-based findings that male voters support more extreme positions than female voters, and link this observation to the "social-harmony" gender gap.