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Anniversary Calculator
Find 100-day, 200-day, 1000-day and yearly anniversaries, with optional day-one counting.
Processed on your device · No file uploads
Your selected files and results are processed on this device. They are not sent to external servers or stored on our servers.
How processing works- 01Select input
- 02Process locally
- 03Review & save
Loading the tool. JavaScript is required.
Example input & result
Input & settings
Start 2026-01-01 · inclusive day 100
Expected result
2026-04-10
Inclusive day N adds N−1 days. Yearly anniversaries use calendar years, not fixed 365-day intervals.
How to use Anniversary Calculator
- 01Choose input values or files.
- 02Check settings and select Calculate or Run.
- 03Review the result and limitations, then save if needed.
Frequently asked questions
Are inputs stored on a server?
No. Inputs and results are processed on-device without uploading or storing them with the operator.
What does this tool do?
Find 100-day, 200-day, 1000-day and yearly anniversaries, with optional day-one counting.
What is an example result?
Start 2026-01-01 · inclusive day 100 → 2026-04-10
What are the limits and assumptions?
Inclusive day N adds N−1 days. Yearly anniversaries use calendar years, not fixed 365-day intervals.
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