There are general guidelines but the real prime time is whenever your specific audience is active. Broad advice points to late afternoons and weekends, yet a channel's own analytics beat any generic rule. For a brand campaign, the creator knows their audience's peak so lean on their data rather than a universal time.
Is there a prime time for posting on YouTube to maximize audience engagement?
General posting-time advice for YouTube exists, often pointing to late afternoons and evenings on weekdays and weekend mornings, when many viewers have free time. But treating any universal time as gospel is the mistake, because the honest truth is that the best time is whenever a particular audience is actually watching and that varies by niche, geography and viewer habits. A channel's own YouTube analytics show exactly when its audience is online, which beats any generic chart. For a brand running an influencer campaign, this is really the creator's territory. They know their audience's rhythms and have the analytics to back it so the practical approach is to trust the creator's judgement on timing rather than impose a rule from outside. Worth being clear that posting optimisation like this is a creator and channel-owner concern, somewhat outside brand-side discovery work. Flinque's part is helping you choose creators whose engaged audience fits your campaign, after which the timing of individual posts is best left to the creator's own data.