1 files changed, 115 insertions, 0 deletions
diff --git a/gallery_dl/dt.py b/gallery_dl/dt.py
new file mode 100644
index 0000000..b37ebf3
--- /dev/null
+++ b/gallery_dl/dt.py
@@ -0,0 +1,115 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2025 Mike Fährmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+"""Date/Time utilities"""
+
+import sys
+import time
+from datetime import datetime, date, timedelta, timezone  # noqa F401
+
+
+class NullDatetime(datetime):
+
+    def __bool__(self):
+        return False
+
+    def __str__(self):
+        return "[Invalid DateTime]"
+
+    def __format__(self, format_spec):
+        return "[Invalid DateTime]"
+
+
+NONE = NullDatetime(1, 1, 1)
+EPOCH = datetime(1970, 1, 1)
+SECOND = timedelta(0, 1)
+
+
+def normalize(dt):
+    #  if (o := dt.utcoffset()) is not None:
+    #      return dt.replace(tzinfo=None, microsecond=0) - o
+    if dt.tzinfo is not None:
+        return dt.astimezone(timezone.utc).replace(tzinfo=None, microsecond=0)
+    if dt.microsecond:
+        return dt.replace(microsecond=0)
+    return dt
+
+
+def convert(value):
+    """Convert 'value' to a naive UTC datetime object"""
+    if not value:
+        return NONE
+    if isinstance(value, datetime):
+        return normalize(value)
+    if isinstance(value, str) and (dt := parse_iso(value)) is not NONE:
+        return dt
+    return parse_ts(value)
+
+
+def parse(dt_string, format):
+    """Parse 'dt_string' according to 'format'"""
+    try:
+        return normalize(datetime.strptime(dt_string, format))
+    except Exception:
+        return NONE
+
+
+if sys.hexversion < 0x30c0000:
+    # Python <= 3.11
+    def parse_iso(dt_string):
+        """Parse 'dt_string' as ISO 8601 value"""
+        try:
+            if dt_string[-1] == "Z":
+                # compat for Python < 3.11
+                dt_string = dt_string[:-1]
+            elif dt_string[-5] in "+-":
+                # compat for Python < 3.11
+                dt_string = f"{dt_string[:-2]}:{dt_string[-2:]}"
+            return normalize(datetime.fromisoformat(dt_string))
+        except Exception:
+            return NONE
+
+    from_ts = datetime.utcfromtimestamp
+    now = datetime.utcnow
+
+else:
+    # Python >= 3.12
+    def parse_iso(dt_string):
+        """Parse 'dt_string' as ISO 8601 value"""
+        try:
+            return normalize(datetime.fromisoformat(dt_string))
+        except Exception:
+            return NONE
+
+    def from_ts(ts=None):
+        """Convert Unix timestamp to naive UTC datetime"""
+        Y, m, d, H, M, S, _, _, _ = time.gmtime(ts)
+        return datetime(Y, m, d, H, M, S)
+
+    now = from_ts
+
+
+def parse_ts(ts, default=NONE):
+    """Create a datetime object from a Unix timestamp"""
+    try:
+        return from_ts(int(ts))
+    except Exception:
+        return default
+
+
+def to_ts(dt):
+    """Convert naive UTC datetime to Unix timestamp"""
+    return (dt - EPOCH) / SECOND
+
+
+def to_ts_string(dt):
+    """Convert naive UTC datetime to Unix timestamp string"""
+    try:
+        return str((dt - EPOCH) // SECOND)
+    except Exception:
+        return ""