I can find your best slots from your own history, but I need post level data with clear time zones first. A generic "Tuesday at 10 am" may not fit your audience; your own numbers will tell us.
What I need (required): 1. One row per post, per platform. Publish date, publish time, impressions (or views) and engagements, for at least the last 8 weeks. "2k, 5k, 800 views" for TikTok has no dates or times, "IG did better on weekends" has no numbers, and LinkedIn has no data yet. TikTok, Meta Business Suite and LinkedIn Page analytics can each export this. 2. The time zone of the export times. "Whatever the app shows" could be London or New York time depending on who pulled it, so each export needs its zone stated. Without it, a post can't be placed in a morning or evening block. 3. Your audience's main time zone. Is your audience mostly in the UK, the US East Coast, or both? I'll convert every post to that zone before grouping.
Defaults I'll apply unless you tell me otherwise: - Platforms: analyzed separately; TikTok, Instagram and LinkedIn are never pooled. - Time blocks: Morning 06:00 to 10:59, Midday 11:00 to 13:59, Afternoon 14:00 to 17:59, Evening 18:00 to 22:59, Late 23:00 to 05:59, in the audience time zone. - Minimum posts per day and block: 3. Fewer shows "too few posts". - Benchmarks: the "Tuesday at 10 am" tip will appear only in a separate labeled block if you give me its source and date. It won't be mixed into your numbers.
Send the exports and time zones, and I'll return the post table, cell table, recommended slots, the too few posts list and a test plan. I won't change any posting schedule without your approval.