Date sequence validator

Date sequence validator is a free browser tool that produces complete source-linked on-screen review and free JSON/CSV results from one exact-text CSV and start date field. Preserve source order.

Free. No account or payment needed.

Your browser is preparing this tool.

What does the date sequence validator produce?

Check real calendar dates, source-row chronology and selected date interval limits within exact groups.

Use the exact local files and task-specific inputs listed below. Preparation and review stay in this browser. Inspect all findings before preparing the finalized pack.

What do you need before you start?

  • Define the authorized source population and your review rules.
  • Keep the unchanged original files and record the snapshot and exclusions.
  • Review missing and invalid inputs before preparing the finalized pack.

What information do you enter?

Select the actual local sources and freeze the task-specific inputs below. Keep source files and complete findings private.

  • One exact-text CSV, one-sheet XLSX or dataset JSON source.
  • Start date field. Exact field name containing YYYY-MM-DD.
  • End date field. Optional exact field name for an interval. Leave blank for chronology only.
  • Sequence group fields. JSON array of existing field names. Use [] for one sequence.
  • Start date ordering. Select the rule before preparing the result.
  • Minimum interval days. Whole days from 0 to 100000. Applies when an end field is selected.
  • Maximum interval days. Whole days from 0 to 100000. Applies when an end field is selected.
Field guidance. The fictional example is invented. Replace it with your own reviewed facts.
FieldWhat to enterFictional example
Start date fieldRequiredExact field name containing YYYY-MM-DD.Start
End date fieldOptionalOptional exact field name for an interval. Leave blank for chronology only.End
Sequence group fieldsRequiredJSON array of existing field names. Use [] for one sequence.
Start date orderingRequiredSelect the rule before preparing the result.Choose from Nondecreasing, Strictly increasing.Nondecreasing
Minimum interval daysRequiredWhole days from 0 to 100000. Applies when an end field is selected.0
Maximum interval daysRequiredWhole days from 0 to 100000. Applies when an end field is selected.7

What you can download

Every result must identify its supplied facts, assumptions and unresolved items.

Free resultIncluded downloads

Enter your information, inspect the on-screen result and keep a browser backup.

Editing and direct copies of your entered information stay free.

  • Complete source-linked on-screen review and free JSON/CSV results.
  • Seven-file finalized pack. Formal PDF and DOCX, complete Excel review, CSV ledger, exact parsed sources and inputs JSON, delivered-file SHA-256 manifest and instructions.
  • Sampled or transformed output dataset where applicable. Exact original files and browser backup ZIP remain separately downloadable.

These supported outputs are free. No checkout is required.

Fictional review report (PDF). Editable review (DOCX). Complete fictional pack (ZIP). Requires tailoring and responsible review. Samples use the finalized renderer.

How does the date sequence validator work?

  1. 1
    Select the actual sources

    One exact-text CSV, one-sheet XLSX or dataset JSON source.

  2. 2
    Freeze the review rules

    Preserve source order. Compare each start date with the preceding row in its exact group. An invalid preceding date leaves that comparison unresolved. Dates count elapsed UTC calendar days, with no legal deadline inference.

  3. 3
    Inspect complete findings

    Review all source-linked results and unresolved items. Free JSON and CSV preserve complete results.

  4. 4
    Keep recoverable work

    Browser-local inputs and exact source files survive reload. Restore a validated exact-byte backup ZIP or explicitly approved private cloud revision. Earlier generic workspace keys, original files and historical purchases remain separate and preserved. Download preserved earlier strings and bytes before changing devices.

  5. 5
    Prepare the finalized pack

    Prepare seven files, then download them free. Review the fictional sample below.

Common questions

What information does the date sequence validator need?

Enter one exact-text CSV, one-sheet XLSX or dataset JSON source; start date field. Exact field name containing YYYY-MM-DD; end date field. Optional exact field name for an interval. Leave blank for chronology only; sequence group fields. JSON array of existing field names. Use [] for one sequence; start date ordering. Select the rule before preparing the result. Define the authorized source population and your review rules.

What does the date sequence validator produce?

Complete source-linked on-screen review and free JSON/CSV results. Seven-file finalized pack. Formal PDF and DOCX, complete Excel review, CSV ledger, exact parsed sources and inputs JSON, delivered-file SHA-256 manifest and instructions. Sampled or transformed output dataset where applicable. Exact original files and browser backup ZIP remain separately downloadable. Review unresolved findings and limitations before use.

Who makes the final decision?

A responsible person reviews the result. Preserve source order. Compare each start date with the preceding row in its exact group. An invalid preceding date leaves that comparison unresolved. Dates count elapsed UTC calendar days, with no legal deadline inference.

Is this tool free?

Yes. The on-screen result and listed downloads are free. No checkout is required. Keep local backups and review the stated method and limits.

Can I use the date sequence validator for this task?

Check specified ordering and interval rules. Preserve source order. Compare each start date with the preceding row in its exact group. An invalid preceding date leaves that comparison unresolved. Dates count elapsed UTC calendar days, with no legal deadline inference.

What still needs review?

Preserve source order. Compare each start date with the preceding row in its exact group. An invalid preceding date leaves that comparison unresolved. Dates count elapsed UTC calendar days, with no legal deadline inference.

Checks do not authenticate source records, population completeness, identifier issuance, external checks, a completed import or compliance.

Use at most 5000 data rows, 50 fields, 100000 cells and 5000000 parsed characters. Up to 10 MB per source. Typed spreadsheet cells, stored formulas and multiple worksheets require an explicit text export.

Formal reports show at most 100 rows and 300 characters per displayed field. Excel and JSON preserve complete results.