diff --git a/python/erc20_demurrage_token/demurrage.py b/python/erc20_demurrage_token/demurrage.py
index 7941ee2..50bad93 100644
--- a/python/erc20_demurrage_token/demurrage.py
+++ b/python/erc20_demurrage_token/demurrage.py
@@ -9,8 +9,7 @@ from chainlib.eth.constant import ZERO_ADDRESS
 # local imports
 from .token import DemurrageToken
 
-logging.basicConfig(level=logging.DEBUG)
-logg = logging.getLogger()
+logg = logging.getLogger(__name__)
 
 
 class DemurrageCalculator:
diff --git a/python/erc20_demurrage_token/unittest/base.py b/python/erc20_demurrage_token/unittest/base.py
index c7eda7c..232043c 100644
--- a/python/erc20_demurrage_token/unittest/base.py
+++ b/python/erc20_demurrage_token/unittest/base.py
@@ -20,7 +20,7 @@ from erc20_demurrage_token import (
         DemurrageToken,
         )
 
-logg = logging.getLogger()
+logg = logging.getLogger(__name__)
 
 #BLOCKTIME = 5 # seconds
 TAX_LEVEL = int(10000 * 2) # 2%
diff --git a/python/tests/test_demurrage.py b/python/tests/test_demurrage.py
new file mode 100644
index 0000000..cd101a9
--- /dev/null
+++ b/python/tests/test_demurrage.py
@@ -0,0 +1,88 @@
+# standard imports
+import datetime
+import unittest
+import logging
+import os
+
+# external imports
+from chainlib.eth.nonce import RPCNonceOracle
+from chainlib.eth.tx import receipt
+
+# local imports
+from erc20_demurrage_token import DemurrageToken
+from erc20_demurrage_token.demurrage import DemurrageCalculator
+
+# test imports
+from erc20_demurrage_token.unittest.base import TestDemurrage
+
+logging.basicConfig(level=logging.INFO)
+logg = logging.getLogger()
+
+
+class TestDemurragePeriods(TestDemurrage):
+
+    def setUp(self):
+        super(TestDemurragePeriods, self).setUp()
+   
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        self.mode = os.environ.get('ERC20_DEMURRAGE_TOKEN_TEST_MODE')
+        if self.mode == None:
+            self.mode = 'MultiNocap'
+        logg.debug('executing test setup default mode {}'.format(self.mode))
+
+        self.deployer.settings.sink_address = self.accounts[9]
+        self.deployer.sink_address = self.accounts[9]
+        self.deploy(c, self.mode)
+
+        logg.info('deployed with mode {}'.format(self.mode))
+
+
+    def test_overtime(self):
+        nonce_oracle = RPCNonceOracle(self.accounts[0], self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        (tx_hash, o) = c.mint_to(self.address, self.accounts[0], self.accounts[1], self.default_supply)
+        r = self.rpc.do(o)
+
+        o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        bob_bal = c.parse_balance(r)
+        prev_bob_bal = bob_bal
+
+        nonce_oracle = RPCNonceOracle(self.sink_address, self.rpc)
+        c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
+
+        for i in range(1, 1001):
+            self.backend.time_travel(self.start_time + (self.period_seconds * i))
+
+            (tx_hash, o) = c.transfer(self.address, self.sink_address, self.accounts[1], prev_bob_bal - bob_bal)
+            r = self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            (tx_hash, o) = c.change_period(self.address, self.sink_address)
+            self.rpc.do(o)
+            o = receipt(tx_hash)
+            r = self.rpc.do(o)
+            self.assertEqual(r['status'], 1)
+
+            o = c.balance(self.address, self.accounts[1], sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            bob_bal = c.parse_balance(r)
+
+            o = c.balance(self.address, self.sink_address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            sink_bal = c.parse_balance(r)
+
+            o = c.total_supply(self.address, sender_address=self.accounts[0])
+            r = self.rpc.do(o)
+            new_supply = c.parse_total_supply(r)
+
+            logg.info('round {} supply {} balance sink {} bob {}'.format(i, new_supply, sink_bal, bob_bal))
+
+
+if __name__ == '__main__':
+    unittest.main()