This singleton run-time message occurs in backtrack every month templates for tokens that have no DayValues, such as in the example below.
[mc+00]
The purpose of this message is to inform you that the token will be processed as if its DayValue was 1.
In most cases, assuming that a missing DayValue is 1 is innocuous, but it does make a difference in backtrack every month templates.
Apart from tokens inside minicalendars, you should always specify the DayValue of every token, to avoid unexpected results.
Topic 188560, last updated on 18-May-2025