From a0866dbc9d1908b57ca614fc11c962673003af0a Mon Sep 17 00:00:00 2001
From: Jason Newman <jason@squarepenguin.com>
Date: Wed, 30 Aug 2017 10:39:46 -0600
Subject: [PATCH] Add support for BC dates

Existing tests check for support for BC datetimes, adds support for BC dates.
---
 encode.go      | 12 ++++++++++--
 encode_test.go |  9 +++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/encode.go b/encode.go
index 88a322cd..3b0d365f 100644
--- a/encode.go
+++ b/encode.go
@@ -367,8 +367,15 @@ func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, erro
 	timeSep := daySep + 3
 	day := p.mustAtoi(str, daySep+1, timeSep)
 
+	minLen := monSep + len("01-01") + 1
+
+	isBC := strings.HasSuffix(str, " BC")
+	if isBC {
+		minLen += 3
+	}
+
 	var hour, minute, second int
-	if len(str) > monSep+len("01-01")+1 {
+	if len(str) > minLen {
 		p.expect(str, ' ', timeSep)
 		minSep := timeSep + 3
 		p.expect(str, ':', minSep)
@@ -424,7 +431,8 @@ func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, erro
 		tzOff = tzSign * ((tzHours * 60 * 60) + (tzMin * 60) + tzSec)
 	}
 	var isoYear int
-	if remainderIdx+3 <= len(str) && str[remainderIdx:remainderIdx+3] == " BC" {
+
+	if isBC {
 		isoYear = 1 - year
 		remainderIdx += 3
 	} else {
diff --git a/encode_test.go b/encode_test.go
index 3a0f7286..837d45be 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -37,6 +37,8 @@ var timeTests = []struct {
 }{
 	{"22001-02-03", time.Date(22001, time.February, 3, 0, 0, 0, 0, time.FixedZone("", 0))},
 	{"2001-02-03", time.Date(2001, time.February, 3, 0, 0, 0, 0, time.FixedZone("", 0))},
+	{"0001-12-31 BC", time.Date(0, time.December, 31, 0, 0, 0, 0, time.FixedZone("", 0))},
+	{"2001-02-03 BC", time.Date(-2000, time.February, 3, 0, 0, 0, 0, time.FixedZone("", 0))},
 	{"2001-02-03 04:05:06", time.Date(2001, time.February, 3, 4, 5, 6, 0, time.FixedZone("", 0))},
 	{"2001-02-03 04:05:06.000001", time.Date(2001, time.February, 3, 4, 5, 6, 1000, time.FixedZone("", 0))},
 	{"2001-02-03 04:05:06.00001", time.Date(2001, time.February, 3, 4, 5, 6, 10000, time.FixedZone("", 0))},
@@ -86,15 +88,22 @@ func TestParseTs(t *testing.T) {
 }
 
 var timeErrorTests = []string{
+	"BC",
+	" BC",
 	"2001",
 	"2001-2-03",
 	"2001-02-3",
 	"2001-02-03 ",
+	"2001-02-03 B",
 	"2001-02-03 04",
 	"2001-02-03 04:",
 	"2001-02-03 04:05",
+	"2001-02-03 04:05 B",
+	"2001-02-03 04:05 BC",
 	"2001-02-03 04:05:",
 	"2001-02-03 04:05:6",
+	"2001-02-03 04:05:06 B",
+	"2001-02-03 04:05:06BC",
 	"2001-02-03 04:05:06.123 B",
 }