Add default DATE_LABEL entry to allow for custom entries?

[deoren]

Example entries from the current dictionary:

# These entries serve both as a mapping of display formats and also as
# valid parameter values. For example, when daily events are requested,
# active daily events will result in notifications generated which have
# subject lines that include the value that is paired with the keyword below.
DATE_LABEL = {
    'daily':TODAY,
    'twice_week':TODAY,
    'weekly':TODAY,
    'weekly_monday':TODAY,
    'weekly_tuesday':TODAY,
    'weekly_wednesday':TODAY,
    'weekly_thursday':TODAY,
    'weekly_friday':TODAY,
    'weekly_saturday':TODAY,
    'weekly_sunday':TODAY,
    'twice_month':TODAY,
    'monthly':MONTH_YEAR,
    'twice_year':MONTH_YEAR,
    'quarterly':MONTH_YEAR,
    'yearly':YEAR
}

As indicated, the earlier line of thought was that if an entry requested via the cron script call wasn't in this dictionary, it wasn't valid and would be rejected.

Perhaps we should instead set a default value to be used for non-matches against this dictionary in order to allow implementations to set a desired keyword within the events table and call that keyword from the cron entry, all without requiring that the script be updated to include a matching entry.

Another, potentially much better option would be to pull that dictionary out and store as a JSON file. The sysadmin would then modify the file as desired in order to extend behavior, all without requiring them to modify the Python source file.