Sunscreen should be reapplied every two hours to assure full coverage while in the sun. Squalane + Zinc Sheer Mineral Sunscreen was designed for everyday wear to protect against incremental sun exposure that happens throughout our day. (going to and from the car, taking kids to school, going to work, etc), and should be good for the day. BIOSSANCE LAB NOTES: Invisible Sun Protection for AllBIOSSANCE LAB NOTES: We've Got You CoveredClick here to view the Zinc Sheer Mineral Sunscreen