[BUG] UTC offset applied globally

The Bright app provides an option to change your timezone relative and to UTC. Unfortunately, this is not particularly helpful as any shift is applied globally.

For instance, the UK entered BST (UTC+1) on Sunday morning. This means that the consumption data reported in the Bright App after March 27th is shifted by an hour and, consequently daily and weekly totals are incorrect. However, if I change my timezone to UTC+1, this applies that change to all readings so that, consumption data for before March 27th is incorrect.

The app should allow users to select their timezone (rather than their different from UTC) and then correctly apply the shift, respecting daylight saving time.

This issue can be sidestepped by using the API and doing the conversion myself, but it would be much better if the app could accommodate daylight saving time.