pelican-plugins/always_modified/always_modified.py

"""
If "modified" date/time is not defined in article metadata, fall back to the "created" date.
"""

from pelican import signals
from pelican.contents import Content, Article

def add_modified(content):
    if not isinstance(content, Article):
        return
    
    if not content.settings.get('ALWAYS_MODIFIED', False):
        return

    if hasattr(content, 'date') and not hasattr(content, 'modified'):
        content.modified = content.date
        content.locale_modified = content.locale_date
    
def register():
    signals.content_object_init.connect(add_modified)