Read Date property from .md for video files

AUTHORS

@@ -54,6 +54,7 @@ alphabetical order):
 - @trapperhoney
 - @tudacs
 - Thomas Misilo
+- Tim AtLee
 - Tim Davies
 - Tobias Preuss
 - Toke Høiland-Jørgensen (@tohojo)

sigal/gallery.py

@@ -4,6 +4,7 @@
 # Copyright (c) 2015      - François D.
 # Copyright (c) 2017      - Mate Lakat
 # Copyright (c) 2018      - Edwin Steele
+# Copyright (c) 2021      - Tim AtLee
 
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to
@@ -294,7 +295,6 @@ class Video(Media):
 
     def __init__(self, filename, path, settings):
         super().__init__(filename, path, settings)
-        self.date = self._get_file_date()
 
         if not settings['use_orig'] or not is_valid_html5_video(self.src_ext):
             video_format = settings['video_format']
@@ -304,6 +304,20 @@ class Video(Media):
         else:
             self.mime = get_mime(self.src_ext)
 
+    @cached_property
+    def date(self):
+        """The date from the Date metadata if available, or from the file date."""
+        # If no date is found in the metadata, return the file date.
+        assetdate = datetime.now()
+        try:
+            assetdate = datetime.fromisoformat(self.meta['date'][0])
+        except:
+            self.logger.debug(
+                "Either self.meta.data was not set, or was in an incorrect format : %s",
+                self.src_filename)
+            assetdate = self._get_file_date()
+        return assetdate
+
 
 class Album:
     """Gather all informations on an album.