Reviewed 1 of 1 files at r1, 5 of 5 files at r2, 4 of 4 files at r3, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @cucaroach and @otan)

pkg/sql/colexec/execgen/cmd/execgen/cast_gen_util.go line 398 at r3 (raw file):

		_now := %[3]s.GetRelativeParseTime()
		_dateStyle := %[3]s.GetDateStyle()
		_d, _, err := pgdate.ParseDate(_now, _dateStyle, string(%[2]s), &evalCtx.ParseHelper)

nit: replace evalCtx with %[3]s as we do for _now and _dateStyle. The rationale is trying to keep the templating more flexible (although in this case the flexibility is probably not worth it since I don't foresee us generating multiple files based on cast_tmpl, still it's better for consistency sake).

pkg/sql/sem/tree/datum.go line 2008 at r3 (raw file):

	// GetDateStyle returns the date style in the session.
	GetDateStyle() pgdate.DateStyle
	// GetParseHelper returns a helper to optmize date parsing

nit: missing period.

pkg/util/timeutil/pgdate/field_extract.go line 78 at r2 (raw file):

	// This indicates that the value in the year field was only
	// two digits and should be adjusted to make it recent.
	tweakYear bool

nit: I'm assuming that the fields are re-arranged to get the object size under some threshold. Consider adding an assertion in init() method that verifies that the size doesn't exceed that threshold.

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @otan and @yuzefovich)

pkg/util/timeutil/pgdate/field_extract.go line 78 at r2 (raw file):

Seems like overkill, I just wanted to save 16 bytes by collapsing bools, it probably didn't move the needle, just seemed like a good idea.