Thanks for your question.
As far as Canada is concerned you can re-enter Canada until November 24, 2016 without any concern at all.
Whether Singapore will say this is good enough or not I cannot know as I am a lawyer in Canada but if you are not sure you can contact their embassy.
Here is a link to their contact information:
Suite 17001095 West Pender StreetBC V6E 2M6VancouverCanada
Does that help as a staring point?
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Is there anything more I can help you with at this point in time?