On 23 July 1914, the Austro-Hungarian Minister of Foreign Affairs Leopold Count Berchtold (pictured) sent a telegram to the Austro-Hungarian Ministers to the Signatory Embassies, the Balkan Missions, and Sweden. In his telegram, he informs the Ambassadors of the delivery of the Austro-Hungarian ultimatum to Serbia to enable them to notify the governments they are accredited to.
Count Berchtold to the Signatory Embassies, the Balkan Missions and the Imperial and Royal Minister to Sweden. Vienna, 23 July 1914.
The presentation of our note in Belgrade did not take place until 18:00 today, Thursday; the term for the answer therefore expires Saturday at 18:00. I beg you to correct the note accordingly.
Source: 1919 Austro-Hungarian Red Book, with minor edits.