When you view a tweet on Twitter, the timestamp displayed shows the local time zone of the device or browser you're using. Here’s how it works:

How Time Zones are Displayed on Twitter

Local Time Zone: The time shown on a tweet reflects the time zone of the device you're using. For example, if you're in New York, the timestamp will show the time in Eastern Time (ET). If you're in Los Angeles, it will show Pacific Time (PT).

Tweet Posting Time: Twitter records the time a tweet is posted in Coordinated Universal Time (UTC) on its servers. However, when you view a tweet, it converts this UTC time to your local time zone.