startTimeUTC is insufficient due to client's clock skew

[igrigorik]

startTimeUTC attribute
The startTimeUTC attribute MUST return a DOMTimeStamp with the time immediately after the User Agent logs the occurrence of the error.

Many client have skewed clocks, which by itself could be causing a number of accessibility issues -- e.g. TLS certificate verification failures. In Beacon, to address this very issue, we set the "Beacon-Age" header indicating the delta between the time when the UA logged the request (error, in this case), and time when it was actually sent. I think we need a similar solution in Error Logging.

That said, assuming we update the spec to support logging of multiple errors in single payload (see #1), we can't re-use the same HTTP header solution. Instead, we would need to introduce a new variable (errorAge or some such), that is set by the UA as the difference between the time when the error occurred and when the error report is being logged. If there is no delay, then it should report 0.

[igrigorik]

• report age instead of fixed time.

[igrigorik]

Resolved in new draft, closing.