SPF 20 filters roughly 95% of UVB rays, which is considered basic protection. It is suitable for regular daytime situations with moderate sun exposure — for example, walking to work, running errands, or sitting near a window. However, it is not designed for prolonged outdoor activities like a beach day, hiking, or a long picnic.
If you plan to stay outdoors for more than 1–2 hours, use a separate sunscreen with SPF 30 or higher as an extra step. Apply it after this cream has absorbed. Also remember that sunscreen effectiveness depends on how much you apply. For the face, a generous amount is about a teaspoon (roughly 2 mg per cm²). If you apply a thin layer, the actual protection is lower than the stated SPF.
Reapplication is also important. Sunscreen should be reapplied every 2 hours, or more often if you sweat or swim. This cream is not designed for reapplication over makeup, so for a long day, consider a sunscreen spray or powder for touch-ups.
If you are indoors most of the day, SPF 20 is a reasonable base, but it still helps to apply a separate sunscreen if you sit near a window or drive frequently.