If you are comparing dayparting tools for Amazon Ads, SellerStack and Off Hours are the two that will keep coming up next to each other. Both schedule bid changes by hour. Both keep the rules readable. Both charge a flat fee instead of a slice of your ad spend. The difference is not in the philosophy, it is in how wide the rule set runs and which Amazon account types you are running.
Full disclosure: this post is written by Off Hours. SellerStack is the closest tool to ours that we have compared on this site, so we have been as exact as we can about where they are the better pick and where we are.
What SellerStack is
SellerStack is Amazon PPC automation software with dayparting at the center. You set bids by hour of day and day of week, or pause and resume whole campaigns on a schedule. Before each bid cut it saves the original value and puts it back afterwards, so a month of nightly cuts cannot walk your bids down over time. Dayparting sits alongside event bid boosts and the rest of their PPC automation.
Three things about it are worth stating plainly, because they are strengths and they are on the pages where a buyer will check.
SellerStack publishes its own hourly research rather than repeating the usual advice. A year-long study of 171 US Amazon accounts found that ACoS in the worst hour ran about 1.8 times the best hour. If you are trying to convince yourself or a client that hour of day actually matters, that is a useful number and it is theirs.
The rules are visible. Their line is that every bid change is tied to a rule you can open and read, and the bid memory behavior backs it up. For sellers who have been burned by a black box, that matters.
Pricing is flat on their Standard and Pro plans, with no percentage of ad spend, and there is a 14-day trial that does not take a card.
What Off Hours is
Off Hours is an Amazon Ads scheduling and automation tool for Amazon Seller Central and Amazon Vendor Central accounts, in all marketplaces across the North America, Europe and Far East regions. It runs dayparting, budget rules, event rules, performance rules and bid adjustments on schedules and conditions the seller defines, checked every 15 minutes across every connected account. Spend Alerts monitors each account's daily spend against its own baseline and is included free on every plan.
Pricing is a flat $149 per month per Amazon Ads account. Off Hours never takes a percentage of ad spend. 15 percent off when billed annually. There is a 14-day free trial and no credit card is required to start.
Every rule is something you can read before it runs: pause these campaigns between 11pm and 6am on weekdays, raise the daily budget by 40 percent for the days around an event and then restore the baseline, step a bid up while trailing ROAS holds above a number you chose. You can see what will happen, and after it happens you can see what fired and why.
Where they genuinely overlap
This is a longer list than it is on most of our comparison pages, and it is worth being honest about.
Both tools are rule based. Both schedule campaign behavior by hour of day and day of week. Both can pause and resume campaigns rather than only rewriting bids. Both keep the rules readable. Both charge a flat fee and neither takes a percentage of ad spend. Both offer a short free trial without a card. Both are built for sellers and agencies who want to decide a rule once and have it run without daily manual work.
The overlap ends at the rule types and the account types. Off Hours carries five rule types in one place: dayparting, budget rules, event rules for tent-pole moments like Prime Day and BFCM, performance rules that react to prior-day metrics like ACoS and spend, and scheduled bid adjustments within a ceiling you set. Its checks run every 15 minutes per connected account. And it works on Seller Central and Vendor Central accounts in all three Amazon regions.
If hour of day is the whole job, the two tools are close enough that the deciding factor is likely something other than the feature list. If you also want budget, event and performance logic in the same scheduler, that is where the two separate.
Who Off Hours is right for
Off Hours fits sellers and agencies who want explicit control over when campaigns run and how budgets move over time, across both seller and vendor accounts.
You will get the most out of it if you run events or a seasonal calendar. Raising a budget into Prime Day or BFCM and restoring it afterwards is a single rule here, not a manual calendar reminder, and the restore is part of the rule rather than something you remember to do.
It fits sellers who think in hours. If you already know that your conversion rate sags between midnight and 6am, or that your category converts better on weekends, dayparting is a direct way to act on that.
It fits sellers who want to see the work. Every rule is readable before it runs and there is a record of what fired and why after. If you have had a tool make unexplained changes to your account, that record is the point.
And it fits agencies and multi-brand operators running Vendor Central and Seller Central side by side, or running accounts in more than one region, since the same rule set and the same flat price apply across all of them.
Who SellerStack is right for
SellerStack fits the same broad audience: sellers and agencies who want rule-based dayparting on Amazon and want the pricing to stay flat as spend grows.
Pick SellerStack if your scheduling need is genuinely hour-of-day bid shaping and day-of-week shaping, and you want the bid-restore behavior that keeps a long run of nightly cuts from eroding your bids. That behavior is well thought through.
Pick it if you want a tool that publishes its own hourly benchmark data, or if the marketplace count matters to you. And pick it if you want event boosts that sit next to dayparting rather than a wider set of rule types in one scheduler. There is nothing wrong with a tool that does a narrower job well, and this one is aimed squarely at the job it does.
Can you use both?
You can, but there is little reason to, and we would not recommend it.
Both tools change bids and both pause and resume campaigns on a schedule. Running them on the same campaigns means two schedulers competing over the same setting, which is the one thing to avoid in any stack. If you already run a bid optimizer, Off Hours dayparting is a clean layer on top because it can work by pause and resume and leave bids alone. Two scheduling tools are a different situation: they are touching the same lever.
If you are deciding between them, map out which tool owns scheduling before you set a single rule, and then only set rules in that one.
What is SellerStack? SellerStack is Amazon PPC automation software with dayparting at its center. It sets bids by hour of day and day of week, or pauses and resumes campaigns, and saves the original bid before each change so bids are restored rather than left drifting. It charges a flat fee rather than a percentage of ad spend, and offers a 14-day trial with no card.
How is Off Hours different from SellerStack? Both are rule based and both schedule by hour. Off Hours covers a wider set of rule types beyond dayparting: dayparting, budget rules, event rules for tent-pole moments, performance rules that react to prior-day metrics, and scheduled bid adjustments, all checked every 15 minutes per connected account. Off Hours supports both Amazon Seller Central and Amazon Vendor Central accounts across the North America, Europe and Far East regions.
Can you run SellerStack and Off Hours together? You can, but there is little reason to. Both change bids and pause or resume campaigns on a schedule, so running them on the same campaigns means two tools competing over the same lever. Pick one to own scheduling. If you use a bid optimizer, Off Hours dayparting is a clean layer on top because it does not have to touch bids.
Which one should I pick? Pick the tool whose rule set matches what you actually run. If hour-of-day bid shaping is the whole job, either works. If you also want budget rules, event ramp-and-restore, performance-triggered changes and vendor accounts in one place, that is Off Hours.
If the wider rule set, the 15-minute cadence and vendor coverage are what you need, Off Hours does that on a flat $149 per month per Amazon Ads account, never a percentage of ad spend. Start a free 14-day trial and build your first rule.