Find Days Since the Start of Year

The Find Days Since the Start of Year Tool helps you calculate how many full days have passed between January 1st and any given date. Whether you’re working on date-based analytics, calendar metrics, or scheduling systems, this tool gives you a quick way to find the “day of year” count for any date you enter.

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Supported file types: .txt, .csv, .log, .json, .xml, .md, .html, .htm, .yaml, .yml, .ini
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How to Use:

  1. Enter Dates: Type or paste one date per line into the input box, using the YYYY-MM-DD format.
  2. Live Preview: The tool instantly calculates how many days have passed since January 1st of that same year.
  3. Import File: Use the Choose File button to load a list of dates from a .txt, .csv, or other supported file.
  4. Copy or Export: Click Copy Output to copy the result to clipboard or Export to File to download it.
  5. Clear All: Hit Clear All to reset the tool and start over.

What Find Days Since the Start of Year Tool can do:

  • Calculates the number of days between January 1st and any valid date in the same year
  • Supports multiple input dates, one per line
  • Flags invalid entries as Invalid date
  • Displays the results live with dynamic output count
  • Accepts safe file import formats like .txt, .csv, .json, and more

Example:

Input:

2024-01-01
2024-02-01
2024-03-15
2024-12-31

Output:

0 days
31 days
74 days
365 days

Days Since the Start of the Year Table:

This live table shows how many full calendar days have passed since January 1st for each of the next 60 days, starting from today. It’s perfect for tracking progress through the year, calculating day-of-year values, or building systems that rely on elapsed calendar time.

DateDays Since January 1st

Common Use Cases:

Use this tool for building or debugging “day of year” calculations, creating countdowns or progress trackers, analyzing seasonality in data, or just understanding how far into the year a date falls. It’s helpful for developers, researchers, planners, and anyone working with date-based logic.

Useful Tools & Suggestions:

To get the full picture, Find Days Till the End of Year shows how much runway you’ve got left. And if you’re aiming for a particular event, Find Days Till a Specific Date lets you zero in on that target.

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