374 CHRONOLOGY, 1879-1902 October 11 December 23 1898, January 3 March 12 April 12 July 30 September 17 October 3 October 10 December 24 1899, January 7 March 11 April 10 July 29 August 1- September 11 September 11 October 9 October 16 October 19 The winter semester at the ETH begins. Classes start on 19 October. The winter vacation begins. Classes resume. Classes at the ETH end. The winter semester ends on 19 March. The summer semester at the ETH begins and classes start. Classes at the ETH end. The summer semester ends on 4 August. Einstein registers at Klosbachstraße 87 in Zurich, where he rooms in the house of Stephanie Markwalder. Start of the oral intermediate examination for the Diplom, which Einstein passes. The winter semester at the ETH begins. Classes start on 18 October. The winter vacation begins. Classes resume. Classes at the ETH end. The winter semester ends on 18 March. Einstein spends the intersession with his family in Milan. The summer semester at the ETH begins and classes start. Classes at the ETH end. The summer semester ends on 3 August. Einstein spends the summer holidays with his mother, sister, and aunt in Mettmenstetten, climbs the Säntis with Maja and visits Aarau. Einstein travels to Milan with his mother and sister. The winter semester at the ETH begins. Classes start on 17 October. Einstein accompanies his sister to Aarau, where she enters the Lehrerinnenseminar as a second-year pupil, and then proceeds to Zurich. Einstein applies for Swiss citizenship.