Assume that we have a SharePoint Farm that is located in the UK. You have several regions and each having their own site collections. There are people uploading documents across the globe. You have a Search Service Application that is crawling the documents. The date format in the UK is DD/MM/YYYY & the date format in the US is MM/DD/YYYY.
For the documents uploaded from the UK sites, in the results returned from the Search Center UI, in the document preview, you see the right format(UK Format). However, for the documents uploaded from the US region, the date format is incorrect in the search results.
Example : When search for the keyword "SharePoint" - The documents containing this word is from US Region - the preview shows last modified date as Wednesday, March 06, 2013. When we checked the properties of the document last modified date is June 03, 2013(06/03/2013). The SharePoint is interpreting this in the format of the UK which is DD/MM/YYYY and it showing as March 06, 2013 and not June 03, 2013.
There is some confusion here around the Date Format.
Without getting into unnecessary detail, we assume US locale when parsing the LastSavedDateTime crawled property.
How to get around it?
1. Access your search service application
2. Select Search Schema
3. Search for LastModifiedTime and Edit
4. Scroll down to the Mappings to crawled Properties section
5. Select the option of Include Content from the first crawled property that is not empty, based on the specified order.
6. Select LastSavedDateTime and click Move Down to move it all the way to the bottom
7. Select Basic:14 and click Move Up to move it all the way to the top.
8. Run a Full Crawl against the content source.
9. Test a search.