diff --git a/src/datepicker/ngb-calendar.spec.ts b/src/datepicker/ngb-calendar.spec.ts
index 94b087c7b4..a60bf48bd5 100644
--- a/src/datepicker/ngb-calendar.spec.ts
+++ b/src/datepicker/ngb-calendar.spec.ts
@@ -44,25 +44,41 @@ describe('ngb-calendar-gregorian', () => {
   });
 
   it('should add months to date', () => {
-    expect(calendar.getNext(new NgbDate(2016, 7, 22), 'm')).toEqual(new NgbDate(2016, 8, 1));
+    expect(calendar.getNext(new NgbDate(2016, 7, 22), 'm')).toEqual(new NgbDate(2016, 8, 22));
     expect(calendar.getNext(new NgbDate(2016, 7, 1), 'm')).toEqual(new NgbDate(2016, 8, 1));
-    expect(calendar.getNext(new NgbDate(2016, 12, 22), 'm')).toEqual(new NgbDate(2017, 1, 1));
+    expect(calendar.getNext(new NgbDate(2016, 12, 22), 'm')).toEqual(new NgbDate(2017, 1, 22));
+    expect(calendar.getNext(new NgbDate(2016, 1, 29), 'm')).toEqual(new NgbDate(2016, 2, 29));
+    expect(calendar.getNext(new NgbDate(2016, 1, 30), 'm')).toEqual(new NgbDate(2016, 2, 29));
+    expect(calendar.getNext(new NgbDate(2016, 10, 30), 'm', 6)).toEqual(new NgbDate(2017, 4, 30));
+    expect(calendar.getNext(new NgbDate(2016, 10, 31), 'm', 6)).toEqual(new NgbDate(2017, 4, 30));
   });
 
   it('should subtract months from date', () => {
-    expect(calendar.getPrev(new NgbDate(2016, 7, 22), 'm')).toEqual(new NgbDate(2016, 6, 1));
+    expect(calendar.getPrev(new NgbDate(2016, 7, 22), 'm')).toEqual(new NgbDate(2016, 6, 22));
     expect(calendar.getPrev(new NgbDate(2016, 8, 1), 'm')).toEqual(new NgbDate(2016, 7, 1));
-    expect(calendar.getPrev(new NgbDate(2017, 1, 22), 'm')).toEqual(new NgbDate(2016, 12, 1));
+    expect(calendar.getPrev(new NgbDate(2017, 1, 22), 'm')).toEqual(new NgbDate(2016, 12, 22));
+    expect(calendar.getPrev(new NgbDate(2016, 3, 29), 'm')).toEqual(new NgbDate(2016, 2, 29));
+    expect(calendar.getPrev(new NgbDate(2016, 3, 30), 'm')).toEqual(new NgbDate(2016, 2, 29));
+    expect(calendar.getPrev(new NgbDate(2016, 10, 30), 'm', 4)).toEqual(new NgbDate(2016, 6, 30));
+    expect(calendar.getPrev(new NgbDate(2016, 10, 31), 'm', 4)).toEqual(new NgbDate(2016, 6, 30));
   });
 
   it('should add years to date', () => {
-    expect(calendar.getNext(new NgbDate(2016, 1, 22), 'y')).toEqual(new NgbDate(2017, 1, 1));
-    expect(calendar.getNext(new NgbDate(2017, 12, 22), 'y')).toEqual(new NgbDate(2018, 1, 1));
+    expect(calendar.getNext(new NgbDate(2016, 1, 22), 'y')).toEqual(new NgbDate(2017, 1, 22));
+    expect(calendar.getNext(new NgbDate(2017, 12, 22), 'y')).toEqual(new NgbDate(2018, 12, 22));
+    expect(calendar.getNext(new NgbDate(2016, 2, 29), 'y')).toEqual(new NgbDate(2017, 2, 28));
+    expect(calendar.getNext(new NgbDate(2016, 2, 28), 'y')).toEqual(new NgbDate(2017, 2, 28));
+    expect(calendar.getNext(new NgbDate(2016, 2, 29), 'y', 4)).toEqual(new NgbDate(2020, 2, 29));
+    expect(calendar.getNext(new NgbDate(2016, 2, 29), 'y', 3)).toEqual(new NgbDate(2019, 2, 28));
   });
 
   it('should subtract years from date', () => {
-    expect(calendar.getPrev(new NgbDate(2016, 12, 22), 'y')).toEqual(new NgbDate(2015, 1, 1));
-    expect(calendar.getPrev(new NgbDate(2017, 1, 22), 'y')).toEqual(new NgbDate(2016, 1, 1));
+    expect(calendar.getPrev(new NgbDate(2016, 12, 22), 'y')).toEqual(new NgbDate(2015, 12, 22));
+    expect(calendar.getPrev(new NgbDate(2017, 1, 22), 'y')).toEqual(new NgbDate(2016, 1, 22));
+    expect(calendar.getPrev(new NgbDate(2016, 2, 28), 'y')).toEqual(new NgbDate(2015, 2, 28));
+    expect(calendar.getPrev(new NgbDate(2016, 2, 29), 'y')).toEqual(new NgbDate(2015, 2, 28));
+    expect(calendar.getPrev(new NgbDate(2016, 2, 29), 'y', 4)).toEqual(new NgbDate(2012, 2, 29));
+    expect(calendar.getPrev(new NgbDate(2016, 2, 29), 'y', 3)).toEqual(new NgbDate(2013, 2, 28));
   });
 
   it('should check that NgbDate is a valid javascript date', () => {
diff --git a/src/datepicker/ngb-calendar.ts b/src/datepicker/ngb-calendar.ts
index 3d50aed8dc..4d00d58835 100644
--- a/src/datepicker/ngb-calendar.ts
+++ b/src/datepicker/ngb-calendar.ts
@@ -43,20 +43,35 @@ export class NgbCalendarGregorian extends NgbCalendar {
 
   getNext(date: NgbDate, period: NgbPeriod = 'd', number = 1) {
     let jsDate = toJSDate(date);
+    let checkMonth = true;
+    let expectedMonth = jsDate.getMonth();
 
     switch (period) {
       case 'y':
-        return new NgbDate(date.year + number, 1, 1);
+        jsDate.setFullYear(jsDate.getFullYear() + number);
+        break;
       case 'm':
-        jsDate = new Date(date.year, date.month + number - 1, 1);
+        expectedMonth += number;
+        jsDate.setMonth(expectedMonth);
+        expectedMonth = expectedMonth % 12;
+        if (expectedMonth < 0) {
+          expectedMonth = expectedMonth + 12;
+        }
         break;
       case 'd':
         jsDate.setDate(jsDate.getDate() + number);
+        checkMonth = false;
         break;
       default:
         return date;
     }
 
+    if (checkMonth && jsDate.getMonth() !== expectedMonth) {
+      // this means the destination month has less days than the initial month
+      // let's go back to the end of the previous month:
+      jsDate.setDate(0);
+    }
+
     return fromJSDate(jsDate);
   }