How can I set the date format to my country setting?

If you want to change the time format to German , you must install the German language from the Language Support and then set the "Regional Settings" in German

languagesupport

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If you want to change the format in Date and Time , you must install dconf-tool . From terminal do

sudo apt-get install dconf-tools

Find it through Dash by writing dconf open it and goto Com > Canonical > Indicator > Datetime and from there you can change the format.

Date-time

Logout and Login for changes to take effect.

The default format is %l:%M %p , you will change it to %M:%l %p

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