diff --git a/rules/en/hour.go b/rules/en/hour.go
index 8958f39..506eb4d 100644
--- a/rules/en/hour.go
+++ b/rules/en/hour.go
@@ -45,6 +45,9 @@ func Hour(s rules.Strategy) rules.Rule {
 			zero := 0
 			switch m.Captures[1][0] {
 			case 65, 97: // am
+				if hour == 12 {
+					hour = 0
+				}
 				c.Hour = &hour
 			case 80, 112: // pm
 				if hour < 12 {
diff --git a/rules/en/hour_minute.go b/rules/en/hour_minute.go
index 868efa3..863377c 100644
--- a/rules/en/hour_minute.go
+++ b/rules/en/hour_minute.go
@@ -62,6 +62,9 @@ func HourMinute(s rules.Strategy) rules.Rule {
 				}
 				switch m.Captures[2][0] {
 				case 65, 97: // am
+					if hour == 12 {
+						hour = 0
+					}
 					c.Hour = &hour
 				case 80, 112: // pm
 					if hour < 12 {
diff --git a/rules/en/hour_minute_test.go b/rules/en/hour_minute_test.go
index ba3a7fd..0785055 100644
--- a/rules/en/hour_minute_test.go
+++ b/rules/en/hour_minute_test.go
@@ -20,6 +20,9 @@ func TestHourMinute(t *testing.T) {
 		{"at 5-59 pm", 3, "5-59 pm", (17 * time.Hour) + (59 * time.Minute)},
 		{"at 17-59 pam", 3, "17-59", (17 * time.Hour) + (59 * time.Minute)},
 		{"up to 11:10 pm", 6, "11:10 pm", (23 * time.Hour) + (10 * time.Minute)},
+		{"12:30am", 0, "12:30am", 30 * time.Minute},
+		{"at 12:00 am", 3, "12:00 am", 0},
+		{"12:30pm", 0, "12:30pm", (12 * time.Hour) + (30 * time.Minute)},
 	}
 
 	fixtnil := []Fixture{
diff --git a/rules/en/hour_test.go b/rules/en/hour_test.go
index d913c41..9dc9795 100644
--- a/rules/en/hour_test.go
+++ b/rules/en/hour_test.go
@@ -21,6 +21,8 @@ func TestHour(t *testing.T) {
 		{"at 5A.", 3, "5A.", 5 * time.Hour},
 		{"5A.", 0, "5A.", 5 * time.Hour},
 		{"11 P.M.", 0, "11 P.M.", 23 * time.Hour},
+		{"at 12 am", 3, "12 am", 0},
+		{"12A.M.", 0, "12A.M.", 0},
 	}
 
 	w := when.New(nil)