Our skin is as different as we are, so the answer to that question varies from person to person and depends on many factors both internal (such as our genetics) and external (such as the amount of sun our skin has been exposed to). As a general rule, a loss of volume and firmness − which leads to less defined facial contours and visible changes in facial features − tends to become a concern between the ages of 40 and 50.  If you are in any doubt please read our article on skin at different ages or consult a pharmacist or dermatologist.

Skin regenerates overnight. As well as moisturizing skin, night creams contain ingredients that stimulate the cell regeneration process. In Eucerin Hyaluron-Filler + Volume-Lift Night that active ingredient is Dexpanthenol which supports skin regeneration overnight. 
Night creams are also SPF free. The day creams in the Eucerin Hyaluron-Filler + Volume-Lift range contain SPF 15 and a UVA filter which makes them suitable for daytime use.