diff --git a/src/main/java/com/github/javafaker/DateAndTime.java b/src/main/java/com/github/javafaker/DateAndTime.java
index ed12549c..45c2fcc1 100644
--- a/src/main/java/com/github/javafaker/DateAndTime.java
+++ b/src/main/java/com/github/javafaker/DateAndTime.java
@@ -144,6 +144,10 @@ public class DateAndTime {
             throw new IllegalArgumentException("Invalid date range, the upper bound date is before the lower bound.");
         }
 
+        if (from.equals(to)) {
+            return from;
+        }
+
         long offsetMillis = faker.random().nextLong(to.getTime() - from.getTime());
         return new Date(from.getTime() + offsetMillis);
     }
@@ -170,8 +174,10 @@ public class DateAndTime {
      */
     public Date birthday(int minAge, int maxAge) {
         int currentYear = Calendar.getInstance().get(Calendar.YEAR);
-        Calendar from = new GregorianCalendar(currentYear - maxAge, 0, 1);
-        Calendar to = new GregorianCalendar(currentYear - minAge, 11, 31);
+        int currentMonth = Calendar.getInstance().get(Calendar.MONTH);
+        int currentDay = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
+        Calendar from = new GregorianCalendar(currentYear - maxAge, currentMonth, currentDay);
+        Calendar to = new GregorianCalendar(currentYear - minAge, currentMonth, currentDay);
 
         return between(from.getTime(), to.getTime());
     }
diff --git a/src/test/java/com/github/javafaker/DateAndTimeTest.java b/src/test/java/com/github/javafaker/DateAndTimeTest.java
index 4c014e53..2d3eb336 100644
--- a/src/test/java/com/github/javafaker/DateAndTimeTest.java
+++ b/src/test/java/com/github/javafaker/DateAndTimeTest.java
@@ -84,10 +84,12 @@ public class DateAndTimeTest extends AbstractFakerTest {
     @Test
     public void testBirthday() {
         int currentYear = Calendar.getInstance().get(Calendar.YEAR);
-        long from = new GregorianCalendar(currentYear - 65, 0, 1).getTime().getTime();
-        long to = new GregorianCalendar(currentYear - 18, 11, 31).getTime().getTime();
+        int currentMonth = Calendar.getInstance().get(Calendar.MONTH);
+        int currentDay = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
+        long from = new GregorianCalendar(currentYear - 65, currentMonth, currentDay).getTime().getTime();
+        long to = new GregorianCalendar(currentYear - 18, currentMonth, currentDay).getTime().getTime();
 
-        for (int i = 0; i < 1000; i++) {
+        for (int i = 0; i < 5000; i++) {
             Date birthday = faker.date().birthday();
             assertThat("birthday is after upper bound", birthday.getTime(), lessThan(to));
             assertThat("birthday is before lower bound", birthday.getTime(), greaterThanOrEqualTo(from));
@@ -97,16 +99,18 @@ public class DateAndTimeTest extends AbstractFakerTest {
     @Test
     public void testBirthdayWithAges() {
         int currentYear = Calendar.getInstance().get(Calendar.YEAR);
+        int currentMonth = Calendar.getInstance().get(Calendar.MONTH);
+        int currentDay = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
 
-        for (int i = 0; i < 1000; i++) {
+        for (int i = 0; i < 5000; i++) {
             int minAge = faker.number().numberBetween(1, 99);
             int maxAge = faker.number().numberBetween(minAge, 100);
 
-            long from = new GregorianCalendar(currentYear - maxAge, 0, 1).getTime().getTime();
-            long to = new GregorianCalendar(currentYear - minAge, 11, 31).getTime().getTime();
+            long from = new GregorianCalendar(currentYear - maxAge, currentMonth, currentDay).getTime().getTime();
+            long to = new GregorianCalendar(currentYear - minAge, currentMonth, currentDay).getTime().getTime();
 
             Date birthday = faker.date().birthday(minAge, maxAge);
-            assertThat("birthday is after upper bound", birthday.getTime(), lessThan(to));
+            assertThat("birthday is after upper bound", birthday.getTime(), lessThanOrEqualTo(to));
             assertThat("birthday is before lower bound", birthday.getTime(), greaterThanOrEqualTo(from));
         }
     }