You would find having such a need in most Yii Projects. Your database needs a specific format to store date fields, while you may want to display it in different formats to the users on forms and other views.
Following on from international dates, I also wanted times in the local timezone and format. This was a little more tricky but I think I've got a solution. This is only really appropriate if you have an international app.
After a lot of research, everything I found on adding date range searching to a CGridView advanced search form seemed to involve adding two new public variables (e.g. $date_from, $date_to), 'safe' rules for the new variables, and a rather chunky if/elseif/else check in the search() method. This probably isn't a hassle for most, but because many of the tables in my database contain two or three and sometimes four date columns (e.g. date_created, date_modified, date_deleted etc.), it meant I was having to add up to eight public variables, the corresponding safe rules, and modifying the search() criteria for each date attribute. So, I set about creating a better way and I thought I'd share my work with the community.
I needed British (dd/mm/yyyy) formatted dates throughout my application but found it very difficult to find examples of how to do this - until I found this excellent forum post http://www.yiiframework.com/forum/index.php?/topic/3649-dealing-with-i18n-date-formats/
This Behaviour helps to view time/date/timestamp/datetime from db to local Date / Time / Date Time format and in local Timezone. And save into db in with db timezone and db format. You only need to include this behaviour in models where need this facility.
The yii2-field-range extension enables you to easily setup ActiveField range fields with Bootstrap styling. You basically can setup two attributes joined together like a single field with combined validation error block.