What is Dayparting?

Dayparting means setting different bids for different hours of the day and days of the week, so that each hour is priced at what its clicks are actually worth. The auction never closes, but shoppers do not behave the same at 3pm and at 3am, and a single flat bid pays the same price for both.

This entry defines the term and its formula. For the full walkthrough, from reading hourly data to running a schedule safely, read the Amazon dayparting guide.

What dayparting means

Every hour carries its own conversion rate, order value and competition, so the same bid buys clicks of very different value. Dayparting measures that difference and prices for it, using two levers that do different jobs:

• The bid sets the price you will pay for a click in that hour. It is the lever that changes efficiency.
• The budget sets how much the campaign may spend in a day. It decides whether you are in the auction at all, not what you pay once you are there.

Dayparting is mostly bid work. Budget only matters when a campaign runs out of money before its best hours arrive.

Amazon's scheduling tools

Schedule bid rules (Sponsored Products) raise bids by a set percentage at the times you choose, and schedule-based budget rules raise a campaign's daily budget on a schedule (Amazon Ads, Bidding rules for Sponsored Products and Amazon Ads API, Schedule-based budget rules, both checked 2026-10-03). Amazon documents both as increases, so the native pattern is a base bid priced for your weakest hours plus a raise for each stronger window.

The formula

ACoS is cost per click divided by revenue per click, so holding an hour at a target ACoS means its CPC has to follow that hour's revenue per click (RPC):

Hour's RPC         = Ad sales in the hour ÷ Clicks in the hour
Hour's target CPC  = Hour's RPC × Target ACoS
Hour's multiplier  = Hour's RPC ÷ Average RPC

The target ACoS is your own number, not a category norm. Start from break-even ACoS, your contribution margin before advertising divided by price, and set the target at or below it.

Worked example

Example inputs, not benchmarks: a campaign has 30 days of hourly data, grouped into two blocks. Its break-even ACoS is 40% and you choose a 30% target.

A flat bid that lands a $0.81 CPC in every hour looks right on the total: $0.81 ÷ $2.70 = 30%. Split it by block and the picture changes:

• Daytime ACoS = $0.81 ÷ $3.00 = 27%, under target, so there is room to bid up.
• Overnight ACoS = $0.81 ÷ $1.50 = 54%, above the 40% break-even, so every overnight order loses money.

The multipliers are 3.00 ÷ 2.70 = 1.11 (about +11%) for daytime and 1.50 ÷ 2.70 = 0.56 (about -44%) overnight. With Amazon's native tools, the same shape means a base bid aimed at the $0.45 overnight price plus a schedule bid rule that doubles it for the daytime window, because $0.90 ÷ $0.45 = 2. The max CPC calculator runs the same arithmetic for any RPC and target.

Using it well

Judge each hour by its revenue per click rather than its order count, group thin hours into blocks, lower a weak hour rather than switching it off, and re-measure after every change, because volume follows bids. Adjustments also stack: in Amazon's own example, a $1.00 bid with a 10% top of search adjustment and a 20% Monday rule bids $1.30 for top of search on Mondays (Amazon Ads, Bidding rules for Sponsored Products, checked 2026-10-03). The Amazon dayparting guide covers reading hourly data, building a schedule step by step and the risks to watch.

How it relates to adjacent metrics

RPC is conversion rate multiplied by average order value, so an hour can be weak because fewer shoppers buy or because they buy less. ACoS is CPC divided by RPC, so the hourly bid has to track RPC to hold the target, and break-even ACoS caps every hour. Placement modifiers and bidding strategies multiply the same bid, and budget rules decide whether the campaign is still running when a good hour arrives. Dayparting shapes the hours; bid optimization sets the level they are shaped around.

How Shurq helps

Shurq's Dayparting page breaks campaign metrics down hour by hour from Amazon Marketing Stream data, including a day of week by time of day heatmap, so you see the shape before changing anything. You can then build a schedule on a seven-day by 24-hour grid, with hours set in the marketplace's own time zone by default. Shurq can propose the grid from your hourly data against a target ACoS you choose, with three modes (Profit, Balanced and Rank) that cap how far above break-even CPC any hour may bid. The proposed grid lowers weak hours rather than switching them off. The schedule runs every hour as changes around your base bid, so the base stays with your own bidding or with Shurq's bid automation, and each hourly change is recorded. An optional budget setting raises a campaign's daily budget only when it caps out while at or under its target. Dayparting is included in Shurq Pro. For a step-by-step walkthrough, see the Amazon dayparting guide.