[time.format] A minor update for LWG 4124

[xmcgcg]

The resolution of LWG 4124 added an exception rule for “omitting chrono-specs”, therefore [time.format] p7 should begin with “unless otherwise specified” to avoid conflicts.

This PR also added two missing commas in [time.format].

[jwakely]

The resolution of LWG 4124 added an exception rule for “omitting chrono-specs”, therefore [time.format] p7 should begin with “unless otherwise specified” to avoid conflicts.

I'm not sure what you mean here, what kind of conflicts?

How would it be otherwise specified? The wording is specifying precisely the case where chrono-specs is omitted in a format-spec which uses this formatter specialization. There is no otherwise possible, is there?

[jwakely]

Oh I see what you mean, p7 says it means one thing, and p18 says otherwise.

But "unless otherwise specified" is always implied. A more specific rule always overrides a more general one.

This wouldn't do any harm though.