Update whats new article with info about time zone selection (#26341)

docs/sources/guides/whats-new-in-v7-1.md

@@ -24,6 +24,7 @@ The main highlights are:
 - [**Transforms**]({{< relref "#transforms" >}})
 - [**Stat panel text mode**]({{< relref "#stat-panel-text-mode" >}})
 - [**Unification of Explore modes**]({{< relref "#explore-modes-unified" >}})
+- [**Time range picker update**]({{< relref "#time-range-picker-update" >}})
 - [**Grafana Enterprise features**]({{< relref "#grafana-enterprise-features" >}})
   - [**Support for HashiCorp Vault**]({{< relref "#support-for-hashicorp-vault" >}})
   - [**Internal links for Elastic**]({{< relref "#internal-links-for-elastic" >}})
@@ -80,6 +81,13 @@ Grafana 7.1 includes a major change to Explore: it removes the query mode select
 
 Many data sources tell Grafana whether a response contains time series data or logs data. Using this information, Explore chooses which visualization to use for that data. This means that you don't need to switch back and forth between Logs and Metrics modes depending on the type of query that you want to make. 
 
+## Time range picker update
+
+With 7.1 we are updating the dashboard's time range picker to allow time zone selection. You no longer need to go to dashboard settings to change the dashboard's time zone.
+
+The time zone picker itself also got UX improvements. Now you can search for the timezone using country or city name, time zone abbreviations, or UTC offsets.    
+
+
 ## Grafana Enterprise features
 
 General features are included in the Grafana Enterprise edition software.