The product information describes ginseng as part of a calm daytime ritual, and the toning effect is associated with daytime use. This makes morning or early afternoon the most natural choice, especially when you need support for focus and energy during the day.
Evening use is less likely because the toning effect may interfere with sleep in sensitive people. The source specifically lists sleep disorders as a reason to consult a specialist before use. If you already have sleep issues or are sensitive to stimulation, it is safer to avoid ginseng late in the day.
The autumn-winter period is also mentioned as a time when ginseng may be especially useful, when there is less sunlight, more tiredness, and daily demands do not ease. If you are returning to an active routine after a period of low energy, a daytime infusion can be a sensible part of your routine. As with any active product, start with a small amount and observe how your body responds.