Calendar date
From Tardis Wiki, the free Doctor Who reference
19 January was the date on which the batteries were changed in the ravens at the Tower of London each year. (PROSE: Time Traveller's Diary [+]Loading...["Time Traveller's Diary (novel)"])
24 January was the date of Blue Monday, which did not always fall on a Monday. It was joyfully celebrated by various species of ultramarine skin colour such as Balhoonians, Crespallions, Stenza and Hooloovoo. (PROSE: Time Traveller's Diary [+]Loading...["Time Traveller's Diary (novel)"])
21 February was the date of the annual Zygon Celebrity-Lookalike Competition. (PROSE: Time Traveller's Diary)
23 November was a mysteriously critical date in the space-time continuum. (PROSE: Time Traveller's Diary)
