Module code_age 

Code age analysis — entity → time since last modification.

Reference date is opts.age_time_now if set, else today (UTC).

What’s emitted (modern default)

For each file (or canonical-lineage entity under --use-canonical-lineage), the analysis emits:

• path — the entity identifier
• age_months — whole calendar months between the latest qualifying commit and the anchor date (interval-month semantics: Mar 15 → Apr 1 = 0 months, not 1 — see inline SQL comment below)
• age_days — whole days between the latest qualifying commit and the anchor — finer-grained precision than code-maat’s months-only output, useful for sort tie-breaking and recency triage
• last_modified — calendar date of the latest qualifying commit (context column — helps the operator see WHEN rather than just HOW LONG AGO)

Code-maat emits only entity, age-months. We add the extra columns because they cost nothing at query time and answer follow-up questions (“how recently?”, “is this a stale stale or a fresh stale?”) without re-running the analysis.

Anchor-date filter

--age-time-now lets the operator anchor the “now” used by the age calculation. To make the back-test pattern (--age-time-now <past>) return historically-faithful results, the SQL filters out commits whose date is AFTER the anchor — same semantics as code-maat’s changes-within-time-span. Without this filter the back-test returned NEGATIVE ages for files modified between the anchor and today, which is meaningless output.

Research basis: see docs/research-foundations.md entry “code-age” (inspired by Dan North’s “short software half-life” talk; quantitative analysis in Tornhill, Your Code as a Crime Scene, 2015).

Structs

CodeAgeRow

Functions

run_code_age