period-freshness: what it makes your agent do, and what it refuses.

period-freshness pulls apart the two dates that look like one: the period a report is about and the moment it was made. Confuse them and the build publishes last period's figures under this period's heading at a green exit code, which is the worst failure this work knows.

The job period-freshness does

A file states up to three dates: a coverage window, an as of instant, and a run stamp. Only the first two describe the data, so this skill gives every date a role, reads each one twice, and lets only the two that describe the data satisfy a period gate. It separates the comparison window from the reporting period so a holiday week cannot inflate a lift, keeps a point in time from being read as a window, and gates staleness against evidence inside the bytes rather than against the filename. When freshness cannot be proved it reports a third state by name, inconclusive, and holds the last good cut instead of publishing a fresh looking wrong one.

What period-freshness refuses

A skill is worth what it stops as much as what it produces. These are the refusals written into period-freshness, taken from the rules and limits in its own file.

✓A run stamp used as proof of period. The stamp records when someone pressed the button, and it is the one date a stale re-export always has fresh.
✓A painted row. Every check it renders is computed on this run and can be turned red by a fire test, and a knob that gates nothing is deleted rather than displayed.
✓A silent pass on an unreadable date. An unparseable or ambiguous date routes through the refusal writer, which still publishes every verdict the surviving rows earned.
✓Fresh and wrong. When the verdict is anything short of a clean pass it fails closed and holds the prior good cut.

9 lines from the period-freshness skill file, verbatim

From skills/period-freshness/SKILL.md, unedited. Kymira skills are plain text you can read in full before you install them, which is the point of shipping a method rather than a binary.

Every check row this skill renders is one the build computes on this run,
with a fire test that can turn that exact row red through the production
pipeline (doctrine 6). A row that cannot change is deleted, not rendered. The
same for configuration: a knob nothing reads (a require_evidence that gates
nothing) is deleted, because an inert setting reports a safety it never
provided. And every blocking path, including an unparseable or ambiguous
date, routes through the refusal-report writer: the customer gets the BLOCKED
page with every verdict the surviving rows earned (doctrine 5), never a stack
trace and an empty folder.

The failure modes period-freshness addresses

These entries in the catalogue of 51 observed failure modes name this skill as what addresses them. Every one was seen in a real build or in our own audits, and none was invented.

The lift a holiday window tripledThe number is plausible, and wrong The date that parses two valid waysThe file lies The calendar forkThe metric means something else The painted rowThe verification is theater The refresh time bombThe wrapper betrays the numbers

The tier period-freshness ships in

Tier	Price	What the tier holds	period-freshness
Free	$0	honest-dataviz and the eleven doctrine principles, published in full	Not in this tier
Core Pack	$199	the thirteen craft skills, one-time purchase, lifetime updates	Included
Everything	$349	all 22 skills, both libraries, the template bank, one-time purchase, lifetime updates	Included

Both paid tiers are a one-time purchase with lifetime updates, and all sales are final: the files are plain text you keep the moment they arrive, so judge the quality on the free skill and the published doctrine first. The pricing section states exactly what each tier contains.

Installing period-freshness

A skill is a folder with a SKILL.md file in it. Installing one is copying that folder where your agent looks for skills, with no build step and no dependencies.

mkdir -p ~/.claude/skills
cp -R Kymira/skills/period-freshness ~/.claude/skills/

Or open the unzipped pack in Claude Code and say install Kymira, which installs every skill in your tier, or double-click the installer for your system. Cursor reads the same skill as a rule file: copy period-freshness.mdc into .cursor/rules/. Skills are read at startup, so start a new session and ask your agent which skills it has available.

Not for

A period pass proves placement, not coverage: a file truncated after week two of a four week month passes cleanly, and this skill says so rather than implying the window was covered. It also cannot tell a settlement timestamp from an order timestamp. Both are dates, both populate, and pointing the period at the wrong one reconciles perfectly.

Last updated 2026-08-30 · Dylan, founder · one of 22 packaged skills, each one a method written down, not a product tour.

See the tiers → All 22 skills The doctrine The failure catalogue