Hi On 2026-09-29 19:17, Tim Düsterhus wrote:
- The behavior of `Instant::toIso8601DateTimeString()` regarding fractional seconds was adjusted again: Trailing zeros will now be kept to make the precision supported by Time\Instant explicit. `2026-09-29T16:42:45.5Z` could mean “exactly 0.5 seconds” or “0.5 seconds ± 0.05 seconds” whereas `2026-09-29T16:42:45.500000000Z` is explicit as to how precise the data is. This might matter for consumers that also store an “uncertainty” range.
Forgot to mention, but it's in the RFC: The fractional part will be entirely omitted if it's zero. While that drops the explicit precision information in *that* case, it should also improve interoperability with consumers who are not prepared to handle fractional seconds. A consumer that already supports fractional seconds should be able to deal with trailing zeros just fine.
Best regards Tim Düsterhus
