Intervals have exact boundary semantics[start, end)
NEXUS CEREBRI / Temporal Lens
Treat time as a typed boundary, not a display string.
Cerebri uses UTC instants, explicit IANA zones and validated half-open intervals, with bounded recurrence diagnostics.
TECHNICAL DEPTH / CONTRACTS
Gap and fold handling must be explicit. Free time is only known under complete coverage; incomplete coverage leaves the complement unknown.
RESEARCH DEPTH / BOUNDARY
Existing daily/weekly series compile into bounded CPIR 0.2 occupancy. Monthly/yearly rules, exceptions, prospective series and recurrence constraints remain unsupported.
TYPED TEMPORAL STATE
A timestamp is not enough to describe time safely.
Cerebri keeps instants, zones, half-open intervals and DST ambiguity explicit so planning does not silently guess what a local clock value means.
TECHNICAL DETAIL
Free-time complements are only known under complete temporal coverage. Gap/fold policy is explicit rather than inferred by the UI.
A local time can fail to existDST gap
A local time can map to two instantsDST fold
Three time paths explain half-open intervals, a DST gap and a DST fold, with raw temporal diagnostic output available in a disclosure.
REALTemporal Lens
UTC INSTANTLOCAL INTERPRETATION
01 / INTERVAL MODEL[start, end)
Touching endpoints do not overlap.
GAP
02 / DST GAP02:30 → nonexistentPolicy must reject or skip.
03 / DST FOLD02:30 → ambiguous
Policy must reject, earlier or later.
Rust temporal fixture output+
{
"status": "Complete",
"data": {
"availability": {
"horizon": {
"start": "2026-03-28T00:00:00Z",
"end": "2026-03-31T00:00:00Z"
},
"coverage": "Complete",
"busy": [
{
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
},
{
"start": "2026-03-28T09:45:00Z",
"end": "2026-03-28T11:05:00Z"
},
{
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
}
],
"free": [
{
"start": "2026-03-28T00:00:00Z",
"end": "2026-03-28T01:30:00Z"
},
{
"start": "2026-03-28T02:00:00Z",
"end": "2026-03-28T09:45:00Z"
},
{
"start": "2026-03-28T11:05:00Z",
"end": "2026-03-30T00:30:00Z"
},
{
"start": "2026-03-30T01:00:00Z",
"end": "2026-03-31T00:00:00Z"
}
],
"unknown": [],
"trace": [
{
"input_index": 0,
"original": {
"start": "2026-03-28T10:00:00Z",
"end": "2026-03-28T11:00:00Z"
},
"buffered": {
"start": "2026-03-28T09:45:00Z",
"end": "2026-03-28T11:05:00Z"
},
"clipped": {
"start": "2026-03-28T09:45:00Z",
"end": "2026-03-28T11:05:00Z"
}
},
{
"input_index": 1,
"original": {
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
},
"buffered": {
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
},
"clipped": {
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
}
},
{
"input_index": 2,
"original": {
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
},
"buffered": {
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
},
"clipped": {
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
}
}
]
},
"expansions": [
{
"horizon": {
"start": "2026-03-28T00:00:00Z",
"end": "2026-03-31T00:00:00Z"
},
"timezone": "Europe/Berlin",
"occurrences": [
{
"sequence": 1,
"date": "2026-03-28",
"local_time": "02:30:00",
"range": {
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
},
"visible_range": {
"start": "2026-03-28T01:30:00Z",
"end": "2026-03-28T02:00:00Z"
},
"resolution": "Unique"
},
{
"sequence": 3,
"date": "2026-03-30",
"local_time": "02:30:00",
"range": {
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
},
"visible_range": {
"start": "2026-03-30T00:30:00Z",
"end": "2026-03-30T01:00:00Z"
},
"resolution": "Unique"
}
],
"skipped": [
{
"sequence": 2,
"date": "2026-03-29",
"reason": "NonexistentLocalTime"
}
],
"examined_dates": 4
}
]
}
}Text alternative
Three time paths explain half-open intervals, a DST gap and a DST fold, with raw temporal diagnostic output available in a disclosure.