Render and accept the minus sign, tweak weights

assets/css/styles.css

@@ -5,7 +5,7 @@
 html {
 	font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"; 
 	font-feature-settings: "case", "tnum", "ss03", "cv09", "cv08", "cv10", "cv11";
-	line-height: 1.5;
+	line-height: 1.4;
 }
 @supports (font-variation-settings: normal) {
 	html {
@@ -204,22 +204,25 @@ d-zoneinfo {
 
 d-zonename {
 	display: inline;
-
-	font-size: 0.75em;
-	font-weight: 600;
 }
 
 d-zoneoffset {
 	display: inline;
 
 	white-space: nowrap;
-	font-size: 0.75em;
 	opacity: 0.5;
 }
+@media (max-width: 675px) {
+	d-zoneoffset {
+		display: block;
+	}
+}
 
 d-date {
-	margin-top: 0.25em;
 	display: block;
+	margin-top: 0.25em;
+
+	font-size: 1.2em;
 }
 
 /* Right container */

zoneoffset.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"regexp"
 	"strconv"
+	"strings"
 )
 
 // ErrZoneOffsetInvalid is thrown when a zone string is an invalid zone offset
@@ -13,7 +14,7 @@ var ErrZoneOffsetInvalid = errors.New("offset zone invalid")
 const zoneHour = 60 * 60
 const zoneMinute = 60
 
-var zoneOffsetRegexp = regexp.MustCompile(`^[+-][0-9]{2}:[0-9]{2}$`)
+var zoneOffsetRegexp = regexp.MustCompile("^[+-\u2212][0-9]{2}:[0-9]{2}$")
 
 // ParseZoneOffset parses a zone string into an offset
 func ParseZoneOffset(zone string) (int, error) {
@@ -23,15 +24,17 @@ func ParseZoneOffset(zone string) (int, error) {
 	// Assume that if it satisfies the regex, it satisfies the length and won't
 	// fail to parse
 	d := 0
-	if zone[0] == '+' {
+	if strings.HasPrefix(zone, "+") {
 		d = 1
 	}
-	if zone[0] == '-' {
+	if strings.HasPrefix(zone, "-") || strings.HasPrefix(zone, "\u2212") {
 		d = -1
 	}
-	h, _ := strconv.ParseUint(zone[1:1+2], 10, 64)
+	zone = strings.TrimLeft(zone, "+-\u2212")
+	parts := strings.Split(zone, ":")
+	h, _ := strconv.ParseUint(parts[0], 10, 64)
 	// Allow hour offsets greater that 24
-	m, _ := strconv.ParseUint(zone[1+3:1+3+2], 10, 64)
+	m, _ := strconv.ParseUint(parts[1], 10, 64)
 	if m >= 60 {
 		return 0, ErrZoneOffsetInvalid
 	}
@@ -44,11 +47,11 @@ func FormatZoneOffset(offset int) string {
 	neg := offset < 0
 	s := '+'
 	if neg {
-		s = '-'
+		s = '\u2212'
 		offset = -offset
 	}
 	if offset == 0 {
-		return "\u00B100:00"
+		return "\u00b100:00"
 	}
 	h := offset / zoneHour
 	m := (offset % zoneHour) / zoneMinute

zoneoffset_test.go

@@ -26,6 +26,16 @@ func TestParseZoneOffset(t *testing.T) {
 		}
 	}
 
+	offset, err = ParseZoneOffset("\u221251:59")
+	if err != nil {
+		t.Errorf("want error %v, got error %v", nil, err)
+	} else {
+		want := -(51*60*60 + 59*60)
+		if offset != want {
+			t.Errorf("got %d, want %d", offset, want)
+		}
+	}
+
 	_, err = ParseZoneOffset("-0030")
 	if err != ErrZoneOffsetInvalid {
 		t.Errorf("want error %v, got error %v", ErrZoneOffsetInvalid, err)
@@ -77,7 +87,7 @@ func TestFormatZoneOffset(t *testing.T) {
 		t.Fatalf("got offset %v, want offset %v", got, want)
 	}
 
-	want, got = "-12:15", FormatZoneOffset(-(12*60*60 + 15*60))
+	want, got = "\u221212:15", FormatZoneOffset(-(12*60*60 + 15*60))
 	if want != got {
 		t.Fatalf("got offset %v, want offset %v", got, want)
 	}