Description
Compare simultaneous supplied zone-span offsets only on explicit UTC intersections, preserving signed right-minus-left and every overlap occurrence.
An offset maps a supplied UTC coordinate to local civil coordinates by local = UTC + offset. Half-open spans include their start and exclude their end. A forward offset jump can leave local coordinates uncovered; a backward jump can give several UTC interpretations of one local value. These tools use explicit synthetic civil-second observations rather than a named-zone database.
Compare simultaneous supplied zone-span offsets only on explicit UTC intersections, preserving signed right-minus-left and every overlap occurrence.
When to use this tool
Use this tool to compare simultaneous supplied zone-span offsets only on explicit UTC intersections, preserving signed right-minus-left and every overlap occurrence.
How to use the tool and how it works
- Enter leftJson, rightJson using the definitions below. Serialize JSON text fields in the decoded shape shown below.
- Run the operation. Resolve input-format errors before interpreting an output.
- Read result.pieces, using the stated boundary, ordering, sign and absence conventions.
Intersect every left/right UTC span pair using start=max(starts), end=min(ends). Keep start<end and report both source indexes and difference=right.offset−left.offset in left-major source order.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| leftJson | JSON array of left {start,end,offset} spans in seconds; start<end, coordinates within ±10¹² and offset within ±86,400. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
| rightJson | JSON array of right offset spans in the same shape, origin and units as leftJson. | Text, at most 8,192 UTF-16 code units; narrower grammar/range rules also apply. |
These decoded structures show the examples inside JSON text fields. Supply their serialized JSON strings as input.
{
"leftJson": [
{
"start": 0,
"end": 2,
"offset": 1
}
],
"rightJson": [
{
"start": 1,
"end": 3,
"offset": 4
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.pieces | Positive-length intersection pieces with the UTC/local endpoints, offsets and original indexes stated above. |
{
"input": {
"leftJson": "[{\"start\":0,\"end\":2,\"offset\":1}]",
"rightJson": "[{\"start\":1,\"end\":3,\"offset\":4}]"
},
"output": {
"result": {
"pieces": [
{
"left": 0,
"right": 0,
"start": 1,
"end": 2,
"difference": 3
}
]
}
}
}Limitations and assumptions
- Touching boundaries have no positive-length intersection. Duplicate or overlapping observations remain separate pieces.
- Span/transition coordinates are finite seconds within ±10¹² and offsets within ±86,400 seconds. Spans require start<end. No IANA database, calendar parsing, daylight-saving inference or leap seconds are included.
- Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
- Ordinary numeric outputs must be finite and within safe-integer magnitude. Exact large lengths/counts use decimal strings. Original record indexes and code-unit positions are zero-based; span ends are exclusive unless stated otherwise.
Alternative or Complementary methods
Keep all timestamps on one origin and in seconds, and retain gaps or competing observations. Use a maintained time-zone library when real dates, named zones or historical rules are required.
References
Similar or alternative tools
- Time Zone Local Ambiguity Classifier
Classify supplied local candidates without claiming missing evidence proves a real civil-clock gap; repeated/overlapping observations remain ambiguous.
- Time Zone Local Candidate Policy Selector
Choose earliest/latest UTC candidate or unique-only under an explicit policy; empty or unresolved evidence returns null.