Description
Measure a household water filter's recorded service-date gap.
Environmental-health records connect sampled matrices, background references, observed areas, service dates and contact durations. An areal loading differs from a bulk or airborne concentration, and a censored result label differs from a quantified value. These summaries do not establish safe conditions or individual health risk.
Measure a household water filter's recorded service-date gap.
When to use this tool
Use Household Water Filter Service Gap when checking the stated environmental-health record, measurement basis or time convention.
How to use the tool and how it works
- Enter lastServiceDate, asOfDate. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedDaysSinceService. Use the output convention below.
Parse real as-of/last-service YYYY-MM-DD dates at UTC midnight. Return asOf-service signedDaysSinceService.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| lastServiceDate | Last Service Date | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| asOfDate | Real YYYY-MM-DD date under the UTC calendar convention specified above. | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedDaysSinceService | Signed Days Since Service | Required. Finite number. |
{
"input": {
"lastServiceDate": "2026-10-01",
"asOfDate": "2026-11-01"
},
"output": {
"signedDaysSinceService": 31
}
}Limitations and assumptions
- Negative ages are retained; no manufacturer interval, actual filter performance or drinking-water safety is determined.
- 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.
Alternative or Complementary methods
Use verified sampling and analytical records with qualified environmental-health professionals for actual exposure, remediation, water-quality or care decisions.
References
Similar or alternative tools
- Bathing Water Sample Date Label
Label a bathing-water specimen with its collection date and location.
- Drinking Water Sample Point Code
Qualify an explicitly supplied drinking-water sampling point by its plan source without assessing water safety.