Find the Date by Day of the Year
Turn an ordinal day number (1-366) back into a calendar date for a chosen year. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use Find the Date by Day of the Year
- 1. Paste the day numbers. Paste one ordinal day number per line into the input pane, such as 195, representing the nth day of the year you want converted.
- 2. Set the year. Enter the Year in the Year field, for example 2026, since the same day number lands on a different date in a leap year versus a common year.
- 3. Copy the resulting dates. Copy the calendar dates from the output pane. Each line matches the day number in the same position from your input.
When to use Find the Date by Day of the Year
Find the Date by Day of the Year converts an ordinal day count, sometimes called a Julian day number, back into a normal calendar date for a chosen year. It is the reverse of counting how many days into the year a date falls.
- Decoding a Julian date stamp. A legacy manufacturing system stamps products with a Julian day number like 195, and converting it back to a calendar date for the current year identifies the exact production date.
- Reading a satellite data log. Scientific datasets often index records by day-of-year number, and converting a batch of those numbers back to calendar dates makes a log readable in a report.
- Interpreting a food expiry code. Some packaged goods print an expiry as a day-of-year number, and converting it against the correct year confirms the actual expiration date before it goes on a shelf label.
- Cross-checking a report. A financial report references day 45 of the fiscal year, and converting that number to a calendar date lets a reader match it against the actual transaction log.
Examples
Day 195 of 2026
Input
195
Output
2026-07-14
First and last day of the year
Input
1 365
Output
2026-01-01 2026-12-31
About the Find the Date by Day of the Year tool
Find the Date by Day of the Year runs as plain JavaScript in your browser tab, with no server behind it. Turn an ordinal day number (1-366) back into a calendar date for a chosen year. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's Time Tools section, 90 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
You can shape the output with the Year setting, and the result refreshes the moment you change it. 2 worked examples further down the page show exactly what the tool produces for real inputs.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Does Find the Date by Day of the Year cost anything?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.
Related tools
All Time Tools →Find the Day of the Year
Find the ordinal day number (1-366) within the year for each calendar date.
Find the Week of the Year
Find the ISO-8601 week number (weeks start Monday) for each calendar date.
Find the Day of the Week
Name the weekday for each calendar date you paste in.
Increment a Calendar Date
Add a number of days, weeks, months or years to each calendar date.