diff --git a/base/univention-network-manager/conffiles/etc/dhcp/dhclient.conf b/base/univention-network-manager/conffiles/etc/dhcp/dhclient.conf
index 7cdf8ce101..2fa39bda7d 100644
--- a/base/univention-network-manager/conffiles/etc/dhcp/dhclient.conf
+++ b/base/univention-network-manager/conffiles/etc/dhcp/dhclient.conf
@@ -71,9 +71,8 @@ reboot 5;
 #}
 @!@
 import random
-import time
 import os.path
-from datetime import datetime
+from datetime import datetime, timedelta
 
 if configRegistry.is_true('dhclient/linklocal/fallback', True):
        for k in configRegistry.keys():
@@ -87,7 +86,7 @@ if configRegistry.is_true('dhclient/linklocal/fallback', True):
                        if not current_addr.startswith('169.254.'):
                                current_addr = '169.254.%s.%s' % (r1, r2)
 
-                       d = datetime.fromtimestamp(time.time() + (6*3600)) # expire in six hours
+                       d = datetime.now() + timedelta(hours=6)  # expire in six hours
 
                        print 'lease {'
                        print '  interface "%s";' % (iface)
@@ -95,7 +94,7 @@ if configRegistry.is_true('dhclient/linklocal/fallback', True):
                        print '  option subnet-mask 255.255.0.0;'
                        print '  option broadcast-address 169.254.255.255;'
                        # Format form 'man dhclient.conf: <weekday> <year>/<month>/<day> <hour>:<minute>:<second>
-                       print '  expire %d %d/%d/%d %s:%s:%s;' % (d.weekday(), d.year, d.month, d.day, str(d.hour).zfill(2), str(d.minute).zfill(2), str(d.second).zfill(2))
+                       print d.strftime('  expire %w %Y/%m/%d %H:%M:%S;')
                        print '}'
 
 LOCAL = '/etc/dhcp/dhclient.conf.local'