by Ravi Kiran Katha on WordPress.org
WP User Timezone displays the front-end dates & times in the browser's local timezone without actually modifying your database.

Plugin configuration
WordPress has a site-level timezone setting configured from the admin back-end. All dates and times displayed on the front-end are typically displayed in this timezone.
This plugin enables the display of dates/times in the front-end using the browser’s timezone. This is done by overriding the WordPress’s ‘timezone_string’ and ‘gmt_offset’ options to match the user’s timezone for the duration of a particular request
ONLY on the front-end interface.
The browser’s timezone is detected using one of the following two methods
jsTimezoneDetect (default)
This is the default timezone detection mechanism. Please refer to the script home page
for the compatibility and other notes
HTML5 Geolocation API
Detects the current geo-location using navigator.geolocation.getCurrentPosition. The location thus detected will be sent to the Google Timezone API
which returns the timezone id – similar to “Asia/Kolkata”.
This method requires you to
If the required options for the usage of Google Timezone API are not met, the detection mechanism falls back to the default one.
This plugin provides a feature to hook into the EventON plugin. When enabled, all EventON dates/times are updated to reflect the browser’s timezone.
This plugin defines the below shortcodes
This plugin defines the below options to retrieve the original timezone_string and gmt_offset defined at the site level
This plugin defines the below filters/hooks
Important: The admin back-end is not modified by this plugin. All dates/times displayed in the back-end are still in the original timezone specified by the WordPress General Settings.