Description
Produce numeric transition calendar marker coordinates on both sides of each jump; no actual Gregorian dates or formatting implied.
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.
Produce numeric transition calendar marker coordinates on both sides of each jump; no actual Gregorian dates or formatting implied.
When to use this tool
Use this tool to produce numeric transition calendar marker coordinates on both sides of each jump; no actual Gregorian dates or formatting implied.
How to use the tool and how it works
- Enter transitionsJson 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.markers, using the stated boundary, ordering, sign and absence conventions.
For each transition return utc=at, localBefore=at+before and localAfter=at+after. Label a positive offset change gap, a negative change fold and equality unchanged, preserving occurrence order.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| transitionsJson | JSON array of {at,before,after} second-valued observations; at is UTC and before/after are signed offsets. | 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.
{
"transitionsJson": [
{
"at": 10,
"before": 0,
"after": 2
},
{
"at": 20,
"before": 2,
"after": 0
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.markers | Source-order {index,utc,localBefore,localAfter,kind} marker records. |
{
"input": {
"transitionsJson": "[{\"at\": 10, \"before\": 0, \"after\": 2}, {\"at\": 20, \"before\": 2, \"after\": 0}]"
},
"output": {
"result": {
"markers": [
{
"index": 0,
"utc": 10,
"localBefore": 10,
"localAfter": 12,
"kind": "gap"
},
{
"index": 1,
"utc": 20,
"localBefore": 22,
"localAfter": 20,
"kind": "fold"
}
]
}
}
}Limitations and assumptions
- Markers are numeric civil-second coordinates rather than parsed calendar dates; no sorting or continuity repair occurs.
- 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 Offset Effective Span Table
Derive bounded half-open UTC effective spans from a complete ordered transition chain, clipping to explicit UTC endpoints.
- Time Zone Transition Local Fold Span
Derive a single transition’s local fold for a negative jump as a half-open interval; other jump signs return null.