# C687 — Connect micro volume to the Actual/Rounded span

## Question

Which equation explains the matching12558→12600 structure across scales?

## Inputs

```json
{
  "micro_count": "69/2",
  "calendar": 364,
  "Actual_pair": [
    14004,
    1446
  ],
  "Rounded_pair": [
    14006,
    1406
  ]
}
```

## Sources

```json
[
  "Supplement A §6; File52c latest; C631 Actual/Rounded interface"
]
```

## Opened utc

2026-09-28T01:13:40.622784+00:00

## Results

```json
{
  "micro_volume_days": 12558,
  "Actual_elapsed_years": 12558,
  "J_completed_numeric": 12600,
  "Rounded_elapsed_years": 12600,
  "identity": "J(364s)=360P(s)"
}
```

## Finding

The micro volume34.5×364 and Actual cumulative interval share the numerical input12558. Their12600 completion follows from364J=360P. This is a common conversion structure across distinct units; the Rounded14006/1406 pair supplies its own endpoint realization.

## Reassessment

Determine why the alternative12740 register is a different calendar choice.

## Checks

```json
{
  "shared_input": true,
  "completion": true,
  "identity": true
}
```

## Closed utc

2026-09-28T01:13:40.623049+00:00

## Record provenance

Exact record hash: `332b3727acd8634833ea09bc05e689c5955eb17f94f698ba4696e00946bdaf58`

Source journal: `Research_Cycles/C0632_C0731/journal.json`