📚 EVEDAYS Guide Book

[Salary]•7 min read

Korean Weekly Holiday Allowance: Rules, Formulas, and Common Mistakes

The three conditions for Korea's weekly holiday allowance, the formulas, worked examples, and the points people most often get wrong, with primary sources.

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[Health]•8 min read

What BMI Does Not Tell You, and How BMR Actually Works

Why WHO and Asia-Pacific BMI cut-offs differ, what BMI cannot see, and how the Mifflin-St Jeor equation and activity factors actually work.

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[Units]•6 min read

Pyeong and Square Meters: Reading Korean Apartment Areas Correctly

The exact pyeong conversion, quick mental shortcuts, and why an 84 m² Korean apartment is called a 34-pyeong unit.

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[Document Security]•7 min read

Redacting PDFs Properly — A Black Box Is Not Redaction

Why covering text with a black box in a PDF is unsafe, what actually works instead, and a practical checklist including metadata.

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[QR Codes]•6 min read

QR Codes: Print Size, Error Correction Levels, and Quishing Risks

Choosing a QR error correction level, sizing for scan distance, the WiFi QR format, and how to avoid quishing attacks.

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[Image Optimization]•6 min read

Shrinking Images the Right Way: Resize First, Then Compress

Why resizing beats lowering quality, which format fits what, stripping EXIF location data, and the effect on LCP.

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[Developer Tools]•6 min read

Five Reasons JSON Fails to Parse, and the Large-Number Trap

Five reasons JSON fails to parse, plus the silent precision loss that corrupts 64-bit IDs when parsed as numbers.

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[Productivity]•6 min read

The Pomodoro Technique as Originally Defined — and Why 25 Minutes Is Not Sacred

The original six-step Pomodoro procedure, how to handle interruptions, and why the 25-minute interval is not sacred.

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