[XENMS] - User joined date (year month day) v1.0.15

• ( [1] days, months, years) = Updated to ( [1] day, month, year).
• The removal of strtolower letter casing has been discontinued.
• Theme settings have been added to enable toggling settings in different themes.
• Instead of changing the participation date, the option to add an additional date has been made available.
• Terminology related to addons has been updated.
• Addon codes have been updated, and date and date format have been separated.
• A new display has been added (year and month).

The code in template changes has been minimized (to prevent issues in external themes).

• The words for day, month, and year have been corrected.
• Abbreviations for day, month, and year have been added.
• The day cycle has been checked.