AI briefings

How periods are compared

Why 'this week' is always compared to the previous comparable week, not the prior 7 days.

3 min readUpdated April 20, 2026

Naive week-over-week comparison is noisy: holidays, reorgs, a single off day can swing a small team's average by 20%. Vibeshift uses comparable-period logic to make deltas meaningful.

The rules

Weekly survey
Compared against the same weekday offset from the previous week.
Biweekly survey
Compared against the same weekday offset two weeks ago, not one.
Monthly survey
Compared against the same calendar month, one year ago when history allows.
Holidays
A known holiday in either period adds a 'holiday-adjusted' caveat to the briefing but does not change the math.

When there's not enough history

For the first few weeks you'll see 'Baseline — no comparison period yet' instead of a delta. This is by design. Once you have 3 comparable periods the briefing switches to delta language.

If the briefing flags a change you don't recognise, click the metric card. The 12-period trend view almost always tells you whether the delta is a real shift or an expected oscillation.

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