[XENMS] - User joined date (year month day) 1.0.16

Made compatible with versions 2.2.X and 2.3.X.
Template modifications have been changed from simple to regular structure to ensure better compatibility with custom themes.
Fixed an issue where the user's day time zone was not displayed when the year and month were selected.

• ( [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.