display time difference & more info in clock off msg; i18n it

aqt/main.py

@@ -808,16 +808,23 @@ title="%s">%s</button>''' % (
     def newMsg(self, data):
         aqt.update.showMessages(self, data)
 
-    def clockIsOff(self):
+    def clockIsOff(self, diff):
-        showWarning("""\
+        warn = _("""\
 In order to ensure your collection works correctly when moved between \
-devices, Anki requires the system clock to be set correctly. Your system \
+devices, Anki requires your computer's internal clock to be set correctly. \
-clock appears to be wrong by more than 5 minutes.
+The internal clock can be wrong even if your system is showing the correct \
+local time.
 
-This can be because the \
+Please go to the time settings on your computer and check the following:
-clock is slow or fast, because the date is set incorrectly, or because \
+
-the timezone or daylight savings information is incorrect. Please correct \
+- AM/PM
-the problem and restart Anki.""")
+- Clock drift
+- Day, month and year
+- Timezone
+- Daylight savings
+
+Difference to correct time: %d seconds.""") % diff
+        showWarning(warn)
         self.app.closeAllWindows()
 
     # Count refreshing

aqt/update.py

@@ -1,14 +1,17 @@
 # Copyright: Damien Elmes <anki@ichi2.net>
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
+import urllib
+import urllib2
+import time
+
 from aqt.qt import *
-import urllib, urllib2, time
 import aqt
-import platform
 from aqt.utils import openLink
-from anki.utils import json, isWin, isMac, platDesc
+from anki.utils import json, platDesc
 from aqt.utils import showText
 
+
 class LatestVersionFinder(QThread):
 
     def __init__(self, main):
@@ -45,7 +48,7 @@ class LatestVersionFinder(QThread):
             self.emit(SIGNAL("newVerAvail"), resp['ver'])
         diff = resp['time'] - time.time()
         if abs(diff) > 300:
-            self.emit(SIGNAL("clockIsOff"))
+            self.emit(SIGNAL("clockIsOff"), diff)
 
 def askAndUpdate(mw, ver):
     baseStr = (