4D2. Non-Gregorian and Old Style/New Style dates:(6)

When the year of publication or printing is based on a calendar in which the year does not begin on January 1, and the publications known to have been published in the following year according to the modern calendar, add the later year in square brackets.(7) If the year of publication or printing is known to be an Old Style (i.e., Julian calendar) date that needs to be adjusted, transcribe it and add the adjustment to New Style in square brackets, but without amending the month and day if present. In case of doubt, do not adjust the year. Example 1

If two consecutive years appear as the publication date, representing both Old and New Styles of dating, transcribe both years, separated by a slash, and add the year according to the modern calendar in square brackets. Example 2