Is this value UTC-based?

Yes, Unix timestamp is UTC-based and timezone neutral.

How often does it refresh?

The display updates every second.

Live epoch values with multiple standardized date representations.

UTC Time

Local Time

ISO 8601

RFC 2822

Unix Timestamp Seconds

Unix Timestamp Milliseconds

Is this value UTC-based?: Yes, Unix timestamp is UTC-based and timezone neutral.
How often does it refresh?: The display updates every second.