add OGC API coverages datetime support

owslib/ogcapi/coverages.py

@@ -58,6 +58,10 @@ def coverage(self, collection_id: str, **kwargs: dict) -> BinaryIO:
         @param scale_factor: factor by which to scale the resulting coverage
         @type scale_axes: list of tuples
         @param scale_axes: [(axis name, number)]
+        @type datetime: tuple | str
+        @param datetime:
+            tuple of start/end datetimes or as 'start/end' string
+            start and end datetimes can be ".." for unbounded value
 
         @returns: coverage data
         """
@@ -85,6 +89,12 @@ def coverage(self, collection_id: str, **kwargs: dict) -> BinaryIO:
         if 'scale_factor' in kwargs:
             kwargs_['scale-factor'] = int(kwargs['scale_factor'])
 
+        if "datetime" in kwargs:
+            if isinstance(kwargs['datetime'], tuple):
+                kwargs_['datetime'] = '/'.join(kwargs['datetime'][:2])
+            else:
+                kwargs_['datetime'] = str(kwargs['datetime'])
+
         path = f'collections/{collection_id}/coverage'
 
         return BytesIO(self._request(path=path, as_dict=False, kwargs=kwargs_))