diff --git a/setup.py b/setup.py
index e82cb88..26918e9 100755
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@ def readme():
 
 
 setup(name='yahoo_fantasy_api',
-      version='2.8.0',
+      version='2.9.0',
       description='Python bindings to access the Yahoo! Fantasy APIs',
       long_description=readme(),
       url='http://github.com/spilchen/yahoo_fantasy_api',
diff --git a/yahoo_fantasy_api/team.py b/yahoo_fantasy_api/team.py
index 02e7155..7ffc806 100644
--- a/yahoo_fantasy_api/team.py
+++ b/yahoo_fantasy_api/team.py
@@ -2,6 +2,7 @@
 
 from yahoo_fantasy_api import yhandler
 import objectpath
+import datetime
 from xml.dom.minidom import Document
 
 from yahoo_fantasy_api.utils import create_element
@@ -113,15 +114,15 @@ def _compact_eligible_pos(j):
             pass
         return roster
 
-    def change_positions(self, day, modified_lineup):
+    def change_positions(self, time_frame, modified_lineup):
         """Change the starting position of a subset of players in your lineup
 
         This raises a RuntimeError if any error occurs when communicating with
         Yahoo!
 
-        :param day: The day that the new positions take affect.  This should be
-            the starting day of the week.
-        :type day: :class:`datetime.date`
+        :param time_frame: The time frame that the new positions take affect.  This should be
+            the starting day of the week (MLB, NBA, or NHL) or the week number (NFL).
+        :type time_frame: :class:`datetime.date` | int
         :param modified_lineup: List of players to modify.  Each entry should
             have a dict with the following keys: player_id - player ID of the
             player to change; selected_position - new position of the player.
@@ -134,7 +135,7 @@ def change_positions(self, day, modified_lineup):
                  {'player_id': 4558, 'selected_position': 'BN'}]
         tm.change_positions(cd, plyrs)
         """
-        xml = self._construct_change_roster_xml(day, modified_lineup)
+        xml = self._construct_change_roster_xml(time_frame, modified_lineup)
         self.yhandler.put_roster(self.team_key, xml)
 
     def add_player(self, player_id):
@@ -377,16 +378,24 @@ def _construct_trade_proposal_xml(self, tradee_team_key: str, your_player_keys:
 
         return doc.toprettyxml()
 
-    def _construct_change_roster_xml(self, day, modified_lineup):
+    def _construct_change_roster_xml(self, time_frame, modified_lineup):
         """Construct XML to pass to Yahoo! that will modified the positions"""
         doc = Document()
         roster = doc.appendChild(doc.createElement('fantasy_content')) \
             .appendChild(doc.createElement('roster'))
 
-        roster.appendChild(doc.createElement('coverage_type')) \
-            .appendChild(doc.createTextNode('date'))
-        roster.appendChild(doc.createElement('date')) \
-            .appendChild(doc.createTextNode(day.strftime("%Y-%m-%d")))
+        if isinstance(time_frame, datetime.date):
+            roster.appendChild(doc.createElement('coverage_type')) \
+                .appendChild(doc.createTextNode('date'))
+            roster.appendChild(doc.createElement('date')) \
+                .appendChild(doc.createTextNode(time_frame.strftime("%Y-%m-%d")))
+        elif isinstance(time_frame, int):
+            roster.appendChild(doc.createElement('coverage_type')) \
+                .appendChild(doc.createTextNode('week'))
+            roster.appendChild(doc.createElement('week')) \
+                .appendChild(doc.createTextNode(str(time_frame)))
+        else:
+            raise RuntimeError("Invalid time_frame format. Must be datetime.date or int.")
 
         plyrs = roster.appendChild(doc.createElement('players'))
         for plyr in modified_lineup:
diff --git a/yahoo_fantasy_api/tests/mock_yhandler.py b/yahoo_fantasy_api/tests/mock_yhandler.py
index 065b01b..1892346 100644
--- a/yahoo_fantasy_api/tests/mock_yhandler.py
+++ b/yahoo_fantasy_api/tests/mock_yhandler.py
@@ -189,3 +189,9 @@ def get_transactions_raw(self, league_id, tran_types, count):
         """
         with open(self.dir_path + "/sample.transactions.json", "r") as f:
             return json.load(f)
+
+    def put_roster(self, team_key, xml):
+        # This produces no output. Just save the xml for inspection by the
+        # test.
+        self.roster_xml = xml
+
diff --git a/yahoo_fantasy_api/tests/test_team.py b/yahoo_fantasy_api/tests/test_team.py
index a15de5b..d4cb175 100644
--- a/yahoo_fantasy_api/tests/test_team.py
+++ b/yahoo_fantasy_api/tests/test_team.py
@@ -1,6 +1,8 @@
 #!/bin/python
 
 import os
+import datetime
+import pytest
 
 
 def test_matchup(mock_team):
@@ -79,3 +81,19 @@ def test__construct_trade_proposal_xml(mock_team):
     actual_xml = mock_team._construct_trade_proposal_xml(tradee_team_key, your_player_keys, their_player_keys, trade_note)
 
     assert actual_xml == expected_xml
+
+
+def test_change_roster(mock_team):
+    plyrs = [{'player_id': 5981, 'selected_position': 'BN'},
+             {'player_id': 4558, 'selected_position': 'BN'}]
+    cd = datetime.date(2019, 10, 7)
+    mock_team.change_positions(cd, plyrs)
+    assert mock_team.yhandler.roster_xml is not None
+    assert "<date>2019-10-07</date>" in mock_team.yhandler.roster_xml
+
+    mock_team.change_positions(2, plyrs)
+    assert "<date>2019-10-07</date>" not in mock_team.yhandler.roster_xml
+    assert "<week>2</week>" in mock_team.yhandler.roster_xml
+
+    with pytest.raises(Exception):
+        mock_team.change_positions("3", plyrs)