This is the official manual for the latest Org-mode release.
The following commands allow you to quickly insert a deadline or to schedule an item:
org-log-redeadline1, a note will be taken when changing an existing deadline.
org-log-reschedule2, a note will be taken when changing an existing scheduling time.
org-deadline-warning-days. With C-u prefix, show all deadlines in the file. With a numeric prefix, check that many days. For example, C-1 C-c / d shows all deadlines due tomorrow.
setting the date by indicating a relative time: e.g., +1d will set
the date to the next day after today, and –1w will set the date
to the previous week before any current timestamp.