diff --git a/vlib/time/custom_format_test.v b/vlib/time/custom_format_test.v
index 6ce238f634..de6bf26c84 100644
--- a/vlib/time/custom_format_test.v
+++ b/vlib/time/custom_format_test.v
@@ -5,34 +5,34 @@ fn test_custom_format() {
 	assert date.custom_format('YYYY-MM-DD HH:mm') == date.format()
 	assert date.custom_format('MMM') == date.smonth()
 
-	test_str := 'M MM Mo MMM MMMM\nD DD DDD DDDD\nd dd ddd dddd\nYY YYYY a A\nH HH h hh k kk e\nm mm s ss Z ZZ ZZZ\nDo DDDo Q Qo QQ\nN NN w wo ww\nM/D/YYYY N-HH:mm:ss Qo?a'
+	test_str := 'M MM Mo MMM MMMM\nD DD DDD DDDD\nd dd ddd dddd\nYY YYYY a A\nH HH h hh k kk i ii e\nm mm s ss Z ZZ ZZZ\nDo DDDo Q Qo QQ\nN NN w wo ww\nM/D/YYYY N-HH:mm:ss Qo?a'
 
 	println(date.custom_format(test_str))
 }
 
 fn test_hours() {
-	assert time.parse('2023-08-04 00:00:45')!.custom_format('hh A h a') == '00 AM 0 am'
-	assert time.parse('2023-08-04 01:00:45')!.custom_format('hh A h a') == '01 AM 1 am'
-	assert time.parse('2023-08-04 02:00:45')!.custom_format('hh A h a') == '02 AM 2 am'
-	assert time.parse('2023-08-04 03:00:45')!.custom_format('hh A h a') == '03 AM 3 am'
-	assert time.parse('2023-08-04 04:00:45')!.custom_format('hh A h a') == '04 AM 4 am'
-	assert time.parse('2023-08-04 05:00:45')!.custom_format('hh A h a') == '05 AM 5 am'
-	assert time.parse('2023-08-04 06:00:45')!.custom_format('hh A h a') == '06 AM 6 am'
-	assert time.parse('2023-08-04 07:00:45')!.custom_format('hh A h a') == '07 AM 7 am'
-	assert time.parse('2023-08-04 08:00:45')!.custom_format('hh A h a') == '08 AM 8 am'
-	assert time.parse('2023-08-04 09:00:45')!.custom_format('hh A h a') == '09 AM 9 am'
-	assert time.parse('2023-08-04 10:00:45')!.custom_format('hh A h a') == '10 AM 10 am'
-	assert time.parse('2023-08-04 11:00:45')!.custom_format('hh A h a') == '11 AM 11 am'
-	assert time.parse('2023-08-04 12:00:45')!.custom_format('hh A h a') == '12 PM 12 pm'
-	assert time.parse('2023-08-04 13:00:45')!.custom_format('hh A h a') == '01 PM 1 pm'
-	assert time.parse('2023-08-04 14:00:45')!.custom_format('hh A h a') == '02 PM 2 pm'
-	assert time.parse('2023-08-04 15:00:45')!.custom_format('hh A h a') == '03 PM 3 pm'
-	assert time.parse('2023-08-04 16:00:45')!.custom_format('hh A h a') == '04 PM 4 pm'
-	assert time.parse('2023-08-04 17:00:45')!.custom_format('hh A h a') == '05 PM 5 pm'
-	assert time.parse('2023-08-04 18:00:45')!.custom_format('hh A h a') == '06 PM 6 pm'
-	assert time.parse('2023-08-04 19:00:45')!.custom_format('hh A h a') == '07 PM 7 pm'
-	assert time.parse('2023-08-04 20:00:45')!.custom_format('hh A h a') == '08 PM 8 pm'
-	assert time.parse('2023-08-04 21:00:45')!.custom_format('hh A h a') == '09 PM 9 pm'
-	assert time.parse('2023-08-04 22:00:45')!.custom_format('hh A h a') == '10 PM 10 pm'
-	assert time.parse('2023-08-04 23:00:45')!.custom_format('hh A h a') == '11 PM 11 pm'
+	assert time.parse('2023-08-04 00:00:45')!.custom_format('ii A i a hh A h a') == '00 AM 0 am 12 AM 12 am'
+	assert time.parse('2023-08-04 01:00:45')!.custom_format('ii A i a hh A h a') == '01 AM 1 am 01 AM 1 am'
+	assert time.parse('2023-08-04 02:00:45')!.custom_format('ii A i a hh A h a') == '02 AM 2 am 02 AM 2 am'
+	assert time.parse('2023-08-04 03:00:45')!.custom_format('ii A i a hh A h a') == '03 AM 3 am 03 AM 3 am'
+	assert time.parse('2023-08-04 04:00:45')!.custom_format('ii A i a hh A h a') == '04 AM 4 am 04 AM 4 am'
+	assert time.parse('2023-08-04 05:00:45')!.custom_format('ii A i a hh A h a') == '05 AM 5 am 05 AM 5 am'
+	assert time.parse('2023-08-04 06:00:45')!.custom_format('ii A i a hh A h a') == '06 AM 6 am 06 AM 6 am'
+	assert time.parse('2023-08-04 07:00:45')!.custom_format('ii A i a hh A h a') == '07 AM 7 am 07 AM 7 am'
+	assert time.parse('2023-08-04 08:00:45')!.custom_format('ii A i a hh A h a') == '08 AM 8 am 08 AM 8 am'
+	assert time.parse('2023-08-04 09:00:45')!.custom_format('ii A i a hh A h a') == '09 AM 9 am 09 AM 9 am'
+	assert time.parse('2023-08-04 10:00:45')!.custom_format('ii A i a hh A h a') == '10 AM 10 am 10 AM 10 am'
+	assert time.parse('2023-08-04 11:00:45')!.custom_format('ii A i a hh A h a') == '11 AM 11 am 11 AM 11 am'
+	assert time.parse('2023-08-04 12:00:45')!.custom_format('ii A i a hh A h a') == '12 PM 12 pm 12 PM 12 pm'
+	assert time.parse('2023-08-04 13:00:45')!.custom_format('ii A i a hh A h a') == '01 PM 1 pm 01 PM 1 pm'
+	assert time.parse('2023-08-04 14:00:45')!.custom_format('ii A i a hh A h a') == '02 PM 2 pm 02 PM 2 pm'
+	assert time.parse('2023-08-04 15:00:45')!.custom_format('ii A i a hh A h a') == '03 PM 3 pm 03 PM 3 pm'
+	assert time.parse('2023-08-04 16:00:45')!.custom_format('ii A i a hh A h a') == '04 PM 4 pm 04 PM 4 pm'
+	assert time.parse('2023-08-04 17:00:45')!.custom_format('ii A i a hh A h a') == '05 PM 5 pm 05 PM 5 pm'
+	assert time.parse('2023-08-04 18:00:45')!.custom_format('ii A i a hh A h a') == '06 PM 6 pm 06 PM 6 pm'
+	assert time.parse('2023-08-04 19:00:45')!.custom_format('ii A i a hh A h a') == '07 PM 7 pm 07 PM 7 pm'
+	assert time.parse('2023-08-04 20:00:45')!.custom_format('ii A i a hh A h a') == '08 PM 8 pm 08 PM 8 pm'
+	assert time.parse('2023-08-04 21:00:45')!.custom_format('ii A i a hh A h a') == '09 PM 9 pm 09 PM 9 pm'
+	assert time.parse('2023-08-04 22:00:45')!.custom_format('ii A i a hh A h a') == '10 PM 10 pm 10 PM 10 pm'
+	assert time.parse('2023-08-04 23:00:45')!.custom_format('ii A i a hh A h a') == '11 PM 11 pm 11 PM 11 pm'
 }
diff --git a/vlib/time/format.v b/vlib/time/format.v
index 79f913610d..1571ed127b 100644
--- a/vlib/time/format.v
+++ b/vlib/time/format.v
@@ -96,8 +96,8 @@ fn ordinal_suffix(n int) string {
 }
 
 const (
-	tokens_2 = ['MM', 'Mo', 'DD', 'Do', 'YY', 'ss', 'kk', 'NN', 'mm', 'hh', 'HH', 'ZZ', 'dd', 'Qo',
-		'QQ', 'wo', 'ww']
+	tokens_2 = ['MM', 'Mo', 'DD', 'Do', 'YY', 'ss', 'kk', 'NN', 'mm', 'hh', 'HH', 'ii', 'ZZ', 'dd',
+		'Qo', 'QQ', 'wo', 'ww']
 	tokens_3 = ['MMM', 'DDD', 'ZZZ', 'ddd']
 	tokens_4 = ['MMMM', 'DDDD', 'DDDo', 'dddd', 'YYYY']
 )
@@ -138,6 +138,8 @@ const (
 // |                  | HH    | 00 01 ... 22 23                        |
 // |                  | h     | 1 2 ... 11 12                          |
 // |                  | hh    | 01 02 ... 11 12                        |
+// |                  | i     | 0 1 ... 11 12 1 ... 11                 |
+// |                  | ii    | 00 01 ... 11 12 01 ... 11              |
 // |                  | k     | 1 2 ... 23 24                          |
 // |                  | kk    | 01 02 ... 23 24                        |
 // |       **Minute** | m     | 0 1 ... 58 59                          |
@@ -232,10 +234,18 @@ pub fn (t Time) custom_format(s string) string {
 				sb.write_string('${t.hour:02}')
 			}
 			'h' {
-				h := if t.hour > 12 { t.hour - 12 } else { t.hour }
+				h := (t.hour + 11) % 12 + 1
 				sb.write_string(h.str())
 			}
 			'hh' {
+				h := (t.hour + 11) % 12 + 1
+				sb.write_string('${h:02}')
+			}
+			'i' {
+				h := if t.hour > 12 { t.hour - 12 } else { t.hour }
+				sb.write_string(h.str())
+			}
+			'ii' {
 				h := if t.hour > 12 { t.hour - 12 } else { t.hour }
 				sb.write_string('${h:02}')
 			}