From reading:
Robyn Annear, ‘Yesterday’s Gone’, The Monthly, September 2014.

[Image by Nicolas Alejandro, Creative Commons]

The words 'yesterday', 'today' and 'tomorrow' are no longer being used by Fairfax because with the move to digital, the same article may be reproduced at different platforms and at different times. The words lose their meaning and instead, the day of the week is used. 'A limitation imposed by new technology has been allowed to spread back into print, undermining the suppleness and the subjectivity of time and language.'

Internationally:

• US - day of the week for print, 'today' for digital
• UK - 'today' for print, day of the week for digital