Switch DatetimePicker start/end to param.Date (#3202)

* Switch DatetimePicker start/end to param.Date

* Update docs

examples/reference/widgets/DatetimePicker.ipynb

@@ -28,12 +28,12 @@
     "##### Core\n",
     "\n",
     "* **``value``** (datetime): The selected value as a datetime type\n",
-    "* **``start``** (date): Start date of the widget\n",
-    "* **``end``** (date): End date of the widget\n",
+    "* **``start``** (date or datetime): Inclusive lower bound of the allowed date selection. Note that while the parameter accepts datetimes the time portion of the range is ignored.\n",
+    "* **``end``** (date or datetime): Inclusive upper bound of the allowed date selection. Note that while the parameter accepts datetimes the time portion of the range is ignored.\n",
     "* **``disabled_dates``** (list): Dates to make unavailable for selection; others will be available\n",
     "* **``enabled_dates``** (list): Dates to make available for selection; others will be unavailable\n",
-    "* **``enable_time:``** (boolean): Enable change of the time in the widget, default is True\n",
-    "* **``enable_seconds:``** (boolean): Enable change of the seconds in the widget, default is True\n",
+    "* **``enable_time:``** (boolean): Enable editing of the time in the widget, default is True\n",
+    "* **``enable_seconds:``**g (boolean): Enable editing of seconds in the widget, default is True\n",
     "* **``military_time:``** (boolean): Enable 24 hours time in the widget, default is True\n",
     "\n",
     "\n",

examples/reference/widgets/DatetimeRangePicker.ipynb

@@ -28,13 +28,13 @@
     "##### Core\n",
     "\n",
     "* **``value``** (tuple): Tuple of upper and lower bounds of the selected range expressed as datetime types\n",
-    "* **``start``** (date): Start date of the widget\n",
-    "* **``end``** (date): End date of the widget\n",
+    "* **``start``** (date or datetime): Inclusive lower bound of the allowed date selection. Note that while the parameter accepts datetimes the time portion of the range is ignored.\n",
+    "* **``end``** (date or datetime): Inclusive upper bound of the allowed date selection. Note that while the parameter accepts datetimes the time portion of the range is ignored.\n",
     "* **``disabled_dates``** (list): Dates to make unavailable for selection; others will be available\n",
     "* **``enabled_dates``** (list): Dates to make available for selection; others will be unavailable\n",
-    "* **``enable_time:``** (boolean): Enable change of the time in the widget, default is True\n",
-    "* **``enable_seconds:``** (boolean): Enable change of the seconds in the widget, default is True\n",
-    "* **``military_time:``** (boolean): Enable 24 hours time in the widget, default is True\n",
+    "* **``enable_time:``** (boolean): Enable editing of the time in the widget, default is True\n",
+    "* **``enable_seconds:``** (boolean): Enable editing of seconds in the widget, default is True\n",
+    "* **``military_time:``** (boolean): Whether to display time in 24 hour format, default is True\n",
     "\n",
     "\n",
     "##### Display\n",

panel/widgets/input.py

@@ -166,19 +166,30 @@ def _process_property_change(self, msg):
 
 class _DatetimePickerBase(Widget):
 
-    start = param.CalendarDate(default=None)
+    disabled_dates = param.List(default=None, class_=(date, str), doc="""
+      Dates to make unavailable for selection.""")
 
-    end = param.CalendarDate(default=None)
+    enabled_dates = param.List(default=None, class_=(date, str), doc="""
+      Dates to make available for selection.""")
 
-    disabled_dates = param.List(default=None, class_=(date, str))
+    enable_time = param.Boolean(default=True, doc="""
+      Enable editing of the time in the widget.""")
 
-    enabled_dates = param.List(default=None, class_=(date, str))
+    enable_seconds = param.Boolean(default=True, doc="""
+      Enable editing of the seconds in the widget.""")
 
-    enable_time = param.Boolean(default=True)
+    end = param.Date(default=None, doc="""
+      Inclusive upper bound of the allowed date selection. Note that while
+      the parameter accepts datetimes the time portion of the range
+      is ignored.""")
 
-    enable_seconds = param.Boolean(default=True)
+    military_time = param.Boolean(default=True, doc="""
+      Whether to display time in 24 hour format.""")
 
-    military_time = param.Boolean(default=True)
+    start = param.Date(default=None, doc="""
+      Inclusive lower bound of the allowed date selection. Note that while
+      the parameter accepts datetimes the time portion of the range
+      is ignored.""")
 
     _source_transforms = {'value': None, 'start': None, 'end': None, 'mode': None}
 
@@ -244,6 +255,7 @@ def _deserialize_value(self, value):
 
 
 class DatetimeRangePicker(_DatetimePickerBase):
+
     value = param.DateRange(default=None)
 
     mode = param.String('range', constant=True)