According to the sources provided, there is no specific time of day that is recommended for taking Lipitor (atorvastatin). However, it is generally recommended to take it at the same time each day to maintain consistent levels of the medication in the body [2][3]. Some studies suggest that taking Lipitor at night may be more effective in reducing cholesterol levels, as the body produces more cholesterol during the night [2]. However, this is not a consensus among healthcare professionals, and the decision of when to take Lipitor should be made in consultation with a healthcare provider [2][3]. It is important to follow the instructions provided by the healthcare provider or the medication label, and not to change the dosage or timing of the medication without consulting a healthcare professional [1][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.drugs.com/medical-answers/does-lipitor-work-better-if-you-take-it-at-night-416127/
[3] https://www.nhs.uk/medicines/atorvastatin/how-and-when-to-take-atorvastatin/