Some Temporal.Instant instances produce identical logging/Deno.inspect output to Date instances

[lionel-rowe]

Temporal.Instant instances with an integer number of epoch milliseconds but not an integer number of seconds produce identical Deno.inspect output to Date instances with the corresponding value:

function log(ns: bigint) {
    const date = new Date(Number(ns / 1_000_000n))
    const instant = Temporal.Instant.fromEpochNanoseconds(ns)

    console.log(date)
    console.log(instant)
    console.log(Deno.inspect(date, { colors: true }) === Deno.inspect(instant, { colors: true }))
}

log(1736321470_000_000_000n)
log(1736321470_888_000_000n)
log(1736321470_888_888_000n)
log(1736321470_888_888_888n)

Output:

2025-01-08T07:31:10.000Z
2025-01-08T07:31:10Z
false
2025-01-08T07:31:10.888Z
2025-01-08T07:31:10.888Z
true
2025-01-08T07:31:10.888Z
2025-01-08T07:31:10.888888Z
false
2025-01-08T07:31:10.888Z
2025-01-08T07:31:10.888888888Z
false

Possible solutions:

• Always show the full 9 ns places for instances of Temporal classes, similar to how the full 3 ms places are always shown for Date instances. However, that leads to unnecessarily verbose output for many cases
• Use different colors/other different formatting

Version: Deno 2.1.4