Practical Guide to Date/Time Calculations

Everything about time data processing from date calculations to timestamp conversion

#date calculation#timestamp#time management#productivity

📋 Table of Contents

1. Date Calculation Fundamentals
2. Timestamp Conversion
3. Practical Use Scenarios
4. Efficient Time Management Tips

Practical Guide to Date/Time Calculations

Date calculations and timestamp conversions are essential in professional work. This guide covers practical date/time handling methods you can apply immediately.

1. Date Calculation Fundamentals

D-Day Calculation

Useful for project deadlines, event D-Days, etc.

const today = new Date();
const dday = new Date('2026-12-31');
const diff = Math.floor((dday - today) / (1000 * 60 * 60 * 24));
console.log(`D-${diff}`);

Working Days Calculation

Calculate actual working days excluding weekends and holidays.

2. Timestamp Conversion

What is Unix Timestamp?

Number of seconds elapsed since January 1, 1970, 00:00:00 UTC.

// Current timestamp
const timestamp = Math.floor(Date.now() / 1000);

// Convert timestamp to date
const date = new Date(timestamp * 1000);
console.log(date.toLocaleString());