> ## Documentation Index
> Fetch the complete documentation index at: https://promostar.app/help/llms.txt
> Use this file to discover all available pages before exploring further.

# How to use PromoStar to pick a subreddit and a time for a post

> Promo Planner lets you search the subreddit pool, star your subs, and start a post at a Prime Time best window. Then choose Save slot or Post now.

Open **Promo Planner**, pick a subreddit, and click one of its suggested windows. The composer opens at a time when strong posts in that sub have tended to land.

## Steps

1. Click **Promo Planner** in the sidebar. Subs you starred show as cards under **Subreddit pool**. Click a card to select it.
2. To use another sub, click **Search the subreddit pool…** and type a name, with or without `r/`. Pick a match, then click the star beside the box to add it to your starred subs. Starred subs also list under **Your subs** on **Home**, where **Plan a post** opens the composer for that sub.
3. Read the **Best windows** line under the cards. It lists the sub's strongest weekday and hour slots. A window marked **early data** rests on very few posts.
4. Click a dashed **best window** chip on the week grid. The composer opens with the sub and the time filled in and marked **Not saved yet**. **New Post** opens the composer at the current time, with its own **Subreddit** search.
5. To move the time, click **Change** beside it. Pick a **Best windows** chip, or open **Custom time** and set **Date** and **Time**, then click **Done**.
6. Choose how to finish at the bottom of the composer:
   * **Save slot** keeps the post on your plan at that time.
   * **Post now** saves the post with the time set to now and opens it on the **Posts** page. If the slot was planned for later, you first choose **Post now** or **Keep the time**.

<Info>
  Windows come from posts PromoStar's collector has observed. A starred sub the collector has not seen yet shows no windows and the note **No recent post data for this subreddit yet**. You can still plan it with **Custom time**.
</Info>

## Good to know

* Times use the zone set under **Settings** > **Preferences** > **Timezone**.
* Windows show when strong posts have tended to land. They do not predict how your post will do, and you can pick any time.
* **Save slot** and **Post now** stay off until a sub is picked.
* Search lists only subs the collector has observed.

## Where processing happens

Sub search, best windows, and saved slots all come from PromoStar's own database. The collector that fills it runs on PromoStar's server and reads only public subreddit listings. It does not read your media.

## Related

* [Find the best time to post](/help/prime-time/find-the-best-time-to-post)
* [Check that a post fits a subreddit](/help/promo-planner/check-that-a-post-fits-a-subreddit)


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