Date Comparison
Show how this period compares with the last one.
What it adds
Period-over-period comparison on analytics figures, with aligned periods, honest handling of incomplete ranges, and sane percentage changes.
What your agent is told to do
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What your agent is told to do
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Offer previous period and same period last year as comparison options, and allow a custom comparison range.
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Make the comparison period exactly the same length as the selected period, and state the compared dates in the UI. An unexplained percentage is not information.
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When the current period is still running, compare like for like — either compare elapsed portions only, or label the figure as partial. Do not compare four days against thirty and call it a decline.
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Do all bucketing and boundary arithmetic in the reporting time zone, and show which time zone that is.
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Show direction with more than colour: an arrow or a sign, so the change is readable to colourblind users and in monochrome print.
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Do NOT build a new range-selection control — the picker is owned by Date Range Picker; read the selected range from it and extend that feature if it needs a comparison mode.
Edge cases it handles
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Edge cases it handles
7- A zero baseline has no percentage change. Show 'no prior data' or the absolute figure, never infinity or a 100% that means nothing.
- A tiny baseline produces absurd percentages — two to six is +200%. Suppress or annotate changes below a minimum sample.
- Month-over-month comparison across months of different lengths must either align by day count or say it is aligning by calendar month.
- Leap days and daylight-saving transitions make some periods 23 or 25 hours long; bucket boundaries must not drift.
- Same period last year should align by weekday for weekly-seasonal metrics, or the comparison is noise.
- Rate metrics do not subtract like counts — a change in conversion rate is percentage points, not percent.
- Late-arriving data will change yesterday's number after you have already shown a comparison; either wait for the data to settle or label recent figures as provisional.
Definition of done
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Definition of done
9- Every comparison states both date ranges explicitly.
- Comparison periods are equal in length to the selected period.
- Incomplete current periods are either elapsed-matched or clearly labelled as partial.
- All boundaries are computed in a stated reporting time zone.
- Zero and near-zero baselines never produce a misleading percentage.
- Direction is conveyed by more than colour alone.
- Range selection continues to be handled by Date Range Picker.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
UI Event Naming Schema
UI Event Naming Schema
Give every tracked interaction a name that still means the same thing in a year.
What it does
A documented vocabulary and structure for event names and properties, applied across the app's existing tracking.
How it works
- 1 Audit the events the app already sends and list them. The duplicates, the near-synonyms, and the ones nobody can explain are the reason the schema is needed, and they are also the migration list.
- 2 Fix a structure of object, action, and context: what was acted on, what happened to it, and where. Fix a closed set of actions — viewed, clicked, opened, submitted, selected, failed — and require every new event to reuse one of them.
- 3 Keep variable detail in properties, never in the name. A record identifier, a plan name, or a workspace slug baked into an event name produces thousands of unaggregatable one-off events.
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No account needed
Add this feature to my app:
https://addthisfeature.com/x/ui-event-naming-schema
Amplitude Event Tracking
Amplitude Event Tracking
Send behavioural events to Amplitude with stable users, devices, and account grouping.
What it does
A server-side pipeline that forwards behavioural events, user properties, and account-level groupings to Amplitude.
How it works
- 1 Identify the behaviours worth measuring and emit them from one place in the application layer, so that the set of events is readable in a single file rather than inferred by grepping the codebase.
- 2 Establish the identity model before writing any send code: what identifies a signed-in user, what identifies a device or anonymous session, and how the two are stitched at sign-up and sign-in.
- 3 Map the app's own tenancy — workspace, organisation, or team — onto Amplitude's group concept, and derive it from the record the event belongs to rather than from whatever context the request happened to carry.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/amplitude-event-tracking
Component Analytics Hook
Component Analytics Hook
Instrument shared components once instead of hand-writing events on every screen.
What it does
Interaction tracking attached to the app's shared components, emitting named events carrying the context of where they were used.
How it works
- 1 Identify the shared components that account for most interaction — buttons, links, menus, dialogs, tabs, table rows, form submits — and attach tracking inside them rather than at each of the hundreds of call sites.
- 2 Have each component emit its own identity and the context it was rendered in: the screen, the surface, and a stable identifier supplied by the caller. Position on the page and visible label are not identity.
- 3 Emit exactly one event per user action. A menu item inside a card inside a table row must not produce three overlapping records of the same click.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/component-analytics-hook
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.