tools (common/date_utils): new get_timezone_name to retrieve it from a tzinfo and a timestamp

sat/tools/common/date_utils.py

@@ -247,3 +247,21 @@ def delta2human(start_ts: Union[float, int], end_ts: Union[float, int]) -> str:
             text_elems.append(f"{value} {unit}")
 
     return ", ".join(text_elems)
+
+
+def get_timezone_name(tzinfo, timestamp: Union[float, int]) -> str:
+    """
+    Get the DST-aware timezone name for a given timezone and timestamp.
+
+    @param tzinfo: The timezone to get the name for
+    @param timestamp: The timestamp to use, as a Unix timestamp (number of seconds since
+        the Unix epoch).
+    @return: The DST-aware timezone name.
+    """
+
+    dt = datetime.datetime.fromtimestamp(timestamp)
+    dt_tz = dt.replace(tzinfo=tzinfo)
+    tz_name = dt_tz.tzname()
+    if tz_name is None:
+        raise exceptions.InternalError("tz_name should not be None")
+    return tz_name