Description
Check reachability of one weekday under a repeating step.
Civil calendar arithmetic needs explicit year numbering, leap rules and index origins. A weekday mask or Gregorian component operation does not identify a timezone, working calendar or historical calendar reform.
Check reachability of one weekday under a repeating step.
When to use this tool
Use Weekday Periodic Step Reachability when checking the stated weekday or Gregorian calendar convention.
How to use the tool and how it works
- Enter start, target, step. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read reachable, steps. Inspect reachable before interpreting the associated values.
Check reachability of one weekday under a repeating step. Require start/target in [0,6]; search zero through six steps with modulo-seven arithmetic, returning first steps or -1 with reachable = false.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| start | Start | Required. Safe integer; minimum 0; maximum 6. |
| target | Target | Required. Safe integer; minimum 0; maximum 6. |
| step | Step duration in the same time unit used by rates and time constants. | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| reachable | Reachable | Required. Boolean. |
| steps | Steps | Required. Safe integer. |
{
"input": {
"start": 1,
"target": 4,
"step": 2
},
"output": {
"reachable": true,
"steps": 5
}
}Limitations and assumptions
- The step may be negative; no real dates, holidays or scheduling constraints are considered.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use an appropriate full calendar library and authoritative local rules when business days, historical dates or real scheduling matter.
References
Similar or alternative tools
- Date: Weekday Mask Bitset Label
Decode a seven-bit weekday mask to labels.
- ISO Weekday Sunday Zero Crosswalk
Convert between ISO weekday numbering and Sunday-zero numbering.