Last Year's BFCM Buyers in Klaviyo: Dates and Time Zone

In our view, customers who bought during your promotion last year make up one of the most useful audiences of a new BFCM. Klaviyo lists this case among the seven key segments for email and SMS on its advanced segmentation page, under the name holiday shoppers segment, and asks you to use last year's BFCM dates in it. It is the date rules, the time zone and the bounds that decide who actually ends up in the segment.

TL;DR. Klaviyo's documentation lets you segment on a metric such as Placed Order with the Between dates period, which includes both the start date and the end date. The segment builder works in UTC, whatever the account's time zone: the bounds fall at midnight UTC, not at your local midnight. A relative condition such as "in the last 30 days" is recalculated once a day for some of the profiles, whereas a fixed-date period, in our view, is not concerned. A segment does not necessarily carry opt-in criteria: in our view, last year's buyers cannot all be reached.

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What Klaviyo offers for holiday shoppers

The advanced segmentation page presents, under the name holiday shoppers, a segment of customers who bought during your Black Friday promotion last year, with the instruction to use last year's BFCM dates in your own segment (Klaviyo, advanced segmentation reference). The suggested use is to invite these customers to this year's offers, show them new products and remind them what made them buy. The page also suggests thinking about cadence around the BFCM weekend, the weekends between the holidays and beyond.

In our view, the window is defined with the dates of your own promotion last year, including any early-access period, and not with those of the retail calendar. Our guide to the 9 BFCM segments describes the other audiences to prepare.

Building the segment

In Klaviyo, creation goes through Audience, Lists & segments, Create, then Segment (Klaviyo, getting started with segments). For the buyers of the period:

1. Add the condition What someone has done (or not done), then the metric Placed Order.
2. Choose the frequency: in our view, at least once.
3. A new condition defaults to in the last 30 days. Change the period with the dropdown, and choose Between dates.
4. Enter the start date and the end date. A calendar appears, with arrows to move from one month to another.

The dates page specifies that every metric on a profile carries a timestamp, which lets you build segments on a specific period (Klaviyo, segmenting with dates reference). Depending on the segment's size, populating can take a while: the getting started page asks you to let the segment populate before scheduling a campaign.

The period options for a metric

For a metric such as Placed Order, the page lists six periods. Its examples take June 17, 2023 as "today".

Two points to note. Between (without dates) reasons in days ago: in our view, a "between 3 and 5 days" window slides every day, so it does not suit a dated promotion. For a window that starts today, the page asks you to use in the last, for example "in the last 30 days" rather than "between 0 and 30 days". In our view, Between dates is the right choice for last year's BFCM, because its bounds do not move.

The time zone: everything happens in UTC

The page is explicit: the segment builder uses the UTC time zone, regardless of the time zone set in your Klaviyo account or on your device. For date conditions on a metric, days start and end at midnight UTC.

In our view, there are two consequences for a shop that sells on Paris time, which is one or two hours ahead of UTC depending on the season: the first hours of the start day can fall outside the segment, and the first hours of the day after the end date can fall inside it. The documentation we reviewed does not quantify this gap for your time zone, so you need to work it out for yours. In our view, you also check the segment's size by comparing it with the number of customers the shop counts for the same period, before loading it into a campaign.

Fixed period or relative condition

Klaviyo distinguishes segments that update in close to real time from those that rely on relative conditions (Klaviyo, understanding how segments update). The page's example: "in the last 30 days" is relative, because the time frame constantly changes, whereas "before January 1, 2025" is not. For a relative condition, a profile whose action makes them qualify or stop qualifying is added or removed as close to real time as possible, while one whom the passage of time alone makes qualify or stop qualifying is added or removed once every 24 hours.

In our view, a window between two fixed dates is not a relative condition: its size does not drift over time. That is the reason to prefer it to a relative condition like "between X and Y days" to find the audience of a past promotion. Segment update delays, up to 15 minutes for a manual update, are detailed in our article on BFCM campaign audiences.

Four variants from the same window

These variants combine conditions documented by Klaviyo.

Buyers from the window who have not bought since. Add a second condition: Placed Order zero times, with the After period and the end date of your promotion. Because After excludes the date itself and starts the next day at midnight UTC, it chains, in our view, with no gap or overlap with Between dates. Join the two conditions with AND: the AND and OR page explains that negative conditions call for AND, and that with OR meeting just one of the conditions is enough (Klaviyo, AND vs. OR reference).

Customers who bought several times. The repeat purchaser page proposes Placed Order at least 2 times, and adapting the period. In our view, the same setting applies to the date window (Klaviyo, how to create a repeat purchaser segment).

Buyers of a collection or a product. Click the filter icon next to the condition, choose a property, then the value with equals or contains. Only top-level properties can be segmented on: for Placed Order, the page cites Value, Collections / Categories, Item Count, Items and Source Name. Values are case sensitive, and only pre-populate if they have already been synced with an event (Klaviyo, getting started with segments).

People who subscribed during the window. Use the rule If someone is in or not in list, choose is and your list, then add the filter was added with Between dates, which includes both dates. This condition looks at the date added to the list, which can differ from the consent date. In our view, this cohort deserves particular caution: people who sign up during a promotion do not all engage afterwards. Our article on the Black Friday waitlist describes how to capture this audience.

Conditions that ignore the year (Day is in month of, Day is today) are for annual events such as birthdays. In our view, they do not fit here, since the year matters. For customer birthdays, see the birthday flow.

A segment is not a send list

The getting started page reminds you of one point: a segment draws from all the contacts in the account and does not necessarily have opt-in criteria. To limit an email segment to subscribers, Klaviyo says to add, with AND, the condition If someone can or cannot receive marketing > can receive > email marketing, then the Subscribed filter under because person. In our view, customers from last year who did not accept emails, or who have unsubscribed since, can therefore appear in the segment. In our view, a segment's size does not tell you the number of recipients: the article on campaign audiences details what removes profiles at send time.

To freeze the audience at a given moment, Klaviyo offers Create list of current members in the Manage segment menu. The action creates a separate, static list of the profiles currently in the segment, while the original segment keeps evolving. In our view, a snapshot is useful to keep a record of a campaign's audience, but it does not replace reading the size just before sending.

Checklist before BFCM

These points are Deliver's advice.

1. The window dates are those of your promotion last year, early access included.
2. The condition is Placed Order, with Between dates, not a relative period.
3. The offset between UTC and your time zone is worked out, and the size is compared with the number of shop customers over the period.
4. Negative conditions (no order since) use AND.
5. The segment is built early enough to be populated before scheduling.
6. The segment name carries the year, to avoid confusion with this year's BFCM.
7. The size is checked against the campaign's real audience, after exclusions and consent.

FAQ

Which dates should you use for last year's buyers segment?

Klaviyo asks you to use last year's BFCM dates in your own segment. In our view, these are the dates of your promotion, early access included.

In which time zone does Klaviyo read the dates of a segment?

In UTC, whatever the time zone of the account or the device. For date conditions on a metric, days start and end at midnight UTC.

Is the end date included in Between dates?

Yes. The page states that the period includes the start date and the end date.

Does the segment update every day?

Relative conditions are recalculated once a day for some of the profiles. In our view, a fixed-date period is not relative, so its size does not drift over time.

Do all the profiles in the segment receive the campaign?

Not necessarily. A segment does not necessarily have opt-in criteria: it draws from all the contacts in the account. In our view, the number of recipients then depends on exclusions, suppressions and consent, which our article on campaign audiences details.

Want an outside look at your BFCM segments? We run Q4 readiness audits, or you can talk directly with the Deliver team.