On 23 July 1914, the Austro-Hungarian Minister of Foreign Affairs Leopold Count Berchtold (pictured) sent a private coded telegram to the Austro-Hungarian Ambassador to Serbia Baron Wladimir Giesl. In his telegram, Berchtold informs Giesl on the procedure to follow when he is to deliver the Austro-Hungarian ultimatum to Serbia. This is one of the key documents of the 1914 July Crisis.
Count Berchtold to Baron von Giesl. Vienna, 23 July 1914.
You will take the step arranged for this afternoon [i.e. the delivery of the Austro-Hungarian ultimatum to Serbia], certainly not at 16:00, but at the earliest a few minutes before 17:00.
If you can possibly arrange matters, postpone the démarche [i.e step] to 18:00, in which case the term of the answer must also be changed to 18:00.
I add for your information that we wish, if it were at all possible, to prevent the news of the démarche from reaching Petersburg this evening, because [French] President Poincaré remains there until 23:00 tonight.
I beg you to telegraph immediately, whether you must deliver note at 17:00, or whether you can postpone démarche until 18:00.
Source: 1919 Austro-Hungarian Red Book, with minor edits