It is reported that very few implementations generate such a diagnostic, and that most implementations correctly handle other contexts. Locales are currently treated as extremely opaque. It is not possible to determine whether two locales are equivalent in a category. A time is normalized according to the following rules. The principle behind normalization is that the date is converted to a number of seconds past some epoch, and then converted back to the correct normalized form.
All dates are in the Gregorian calendar.
This shall then be used to determine the number of days in the year prior to the month. Apart from this, the final date can be determined simply by adding together the various fields, each with a suitable weight, to get the number of seconds past the epoch. The normalization should be exact provided that there is no unreasonable overflow.