Magento2: Calendar. Time format 24h

[OleksiyOleksiyovych]

Steps to reproduce

1. Install Magento from develop or master branch.
2. Create custom extension and try to use calendar.
3. https://www.dropbox.com/s/xxzjp3vn2z6jskg/Screenshot%202016-03-22%2010.10.06.png

$("#datatime").calendar({
       timeFormat: "HH:mm:ss",
});

Expected result

1. We want to see 24h format, like 21:34:45 (does not 9:34:45 PM).

   Actual result

2. We have AM/PM fromat

   Reason

File /lib/web/mage/calendar.js
Lines 396-400

time: {
      'a': 'tt',
      'HH': 'hh',
      'H': 'h'
}

This mask change string format

• from 'HH:mm:ss' to 'hh:mm:ss'
• from 'H:mm:ss' to 'h:mm:ss'

Why do we need this transformations?

[guz-anton]

Why do we need this transformations?

Because main producer for date-time configuration is Backend (Php app with ICU datetime format).

[OleksiyOleksiyovych]

Ok, but can I set 24h time format in calendar?

[kumbas1]

Currently there is fix for issue MAGETWO-52178 waiting to be merged in mainline.

[guz-anton]

Fix was deivered to mainline (develop branch).