diff --git a/pandas_datareader/yahoo/daily.py b/pandas_datareader/yahoo/daily.py
index e1578b09..26120642 100644
--- a/pandas_datareader/yahoo/daily.py
+++ b/pandas_datareader/yahoo/daily.py
@@ -3,6 +3,7 @@
 import json
 import re
 import time
+import datetime
 
 from pandas import DataFrame, isnull, notnull, to_datetime
 
@@ -127,7 +128,8 @@ def url(self):
     def _get_params(self, symbol):
         # This needed because yahoo returns data shifted by 4 hours ago.
         four_hours_in_seconds = 14400
-        unix_start = int(time.mktime(self.start.timetuple()))
+        unix_zero = datetime.datetime(1970, 1, 1, 8)
+        unix_start = int((self.start - unix_zero).total_seconds())
         unix_start += four_hours_in_seconds
         day_end = self.end.replace(hour=23, minute=59, second=59)
         unix_end = int(time.mktime(day_end.timetuple()))
diff --git a/pandas_datareader/yahoo/fx.py b/pandas_datareader/yahoo/fx.py
index 81a0f0ec..69e15f1c 100644
--- a/pandas_datareader/yahoo/fx.py
+++ b/pandas_datareader/yahoo/fx.py
@@ -1,5 +1,6 @@
 import json
 import time
+import datetime
 import warnings
 
 from pandas import DataFrame, Series, concat, to_datetime
@@ -39,7 +40,8 @@ class YahooFXReader(YahooDailyReader):
     """
 
     def _get_params(self, symbol):
-        unix_start = int(time.mktime(self.start.timetuple()))
+        unix_zero = datetime.datetime(1970, 1, 1, 8)
+        unix_start = int((self.start - unix_zero).total_seconds())
         day_end = self.end.replace(hour=23, minute=59, second=59)
         unix_end = int(time.mktime(day_end.timetuple()))