A timestamp may be preceded by special keywords to facilitate planning:
On
the deadline date, the task will be listed in the agenda. In
addition, the agenda for today will carry a warning
about the approaching or missed deadline, starting
org-deadline-warning-days before the due date,
and continuing until the entry is marked DONE. An
example:
*** TODO write article about the Earth for the Guide
The editor in charge is [[bbdb:Ford Prefect]]
DEADLINE: <2004-02-29 Sun>
You can specify a different lead time for warnings for a
specific deadlines using the following syntax. Here is an
example with a warning period of 5 days DEADLINE:
<2004-02-29 Sun -5d>.
The headline will be listed under the given date1. In addition, a reminder that the scheduled date has passed will be present in the compilation for today, until the entry is marked DONE, i.e. the task will automatically be forwarded until completed.
*** TODO Call Trillian for a date on New Years Eve.
SCHEDULED: <2004-12-25 Sat>
Important: Scheduling an item in Org-mode should not be understood in the same way that we understand scheduling a meeting. Setting a date for a meeting is just a simple appointment, you should mark this entry with a simple plain timestamp, to get this item shown on the date where it applies. This is a frequent misunderstanding by Org users. In Org-mode, scheduling means setting a date when you want to start working on an action item.
You may use timestamps with repeaters in scheduling and
deadline entries. Org-mode will issue early and late warnings
based on the assumption that the timestamp represents the
nearest instance of the repeater. However, the use of
diary sexp entries like <%%(diary-float t 42)>
in scheduling and deadline timestamps is limited. Org-mode does
not know enough about the internals of each sexp function to
issue early and late warnings. However, it will show the item on
each day where the sexp entry matches.
[1] It will still be listed on that date
after it has been marked DONE. If you don't like this, set the
variable org-agenda-skip-scheduled-if-done.