I was using http://www.mywebsite.com/category/postname for 2 years now.
Now, i have changed it to http://www.mywebsite.com/year/month/postname.
So, I want to redirect my old url to new one as some bookmarks and links are pointing toward my old urls.
Google have also indexed my content with old URL. And it has started to re-index it using my new URL also.
When I checked HTML Suggestions in my Webmaster Tool, it is showing Duplicate title tags, Duplicate meta descriptions, because of the two urls with same content.
I know I can redirect my old URL to new using 301 redirect. But, as my blog have more than 1000 posts it will be time consuming to redirect each and every URL.
Any method to mass redirect my old URLs to new ones? And how should I inform Google or any other search engine about the same?