Timestamp Best Practices for Web Development

Timestamp Best Practices

Handling time correctly is one of the trickiest parts of software development. Follow these best practices to avoid common pitfalls.

1. Store in UTC

Always store timestamps in UTC (Coordinated Universal Time):

``javascript


// Good: Store UTC timestamp
const utcTimestamp = Date.now();
database.save({ created_at: utcTimestamp });
// Bad: Store local time
const localTime = new Date().toString();  // Includes timezone

Benefits:


Consistent across servers worldwide
No daylight saving time issues
Easy to convert to any local time

2. Use Integers, Not Strings
Store timestamps as integers, not formatted strings:

`sql


-- Good
created_at BIGINT NOT NULL
-- Bad
created_at VARCHAR(50)

Benefits:


Smaller storage size
Faster comparisons and sorting
No parsing errors

3. Display in User's Local Time
Convert to local time only when displaying to users:

`javascript


// API returns UTC timestamp
const apiTimestamp = 1735689600000;
// Convert for display
const localDate = new Date(apiTimestamp);
const displayString = localDate.toLocaleString();

`4. Be Explicit About Units`

Always document whether you're using seconds or milliseconds:

`typescript


interface ApiResponse {
  // Unix timestamp in seconds
  created_at: number;
  // Unix timestamp in milliseconds
  updated_at_ms: number;
}

`5. Handle Time Zones Carefully`

When accepting user input, be clear about time zones:

`javascript


// Parse with explicit timezone
const userDate = new Date('2025-01-15T10:00:00-05:00');  // EST
// Or parse as UTC
const utcDate = new Date('2025-01-15T15:00:00Z');

`6. Use Libraries for Complex Operations`

For complex date manipulation, use established libraries:

`javascript


// date-fns
import { addDays, format } from 'date-fns';
const nextWeek = addDays(new Date(), 7);
// dayjs
import dayjs from 'dayjs';
const formatted = dayjs().format('YYYY-MM-DD');

`7. Validate Timestamp Ranges`

Always validate timestamp inputs:

`javascript


function isValidTimestamp(ts) {
  // Check reasonable range (1970 to 2100)
  const minTs = 0;
  const maxTs = 4102444800; // 2100-01-01
  return Number.isInteger(ts) && ts >= minTs && ts <= maxTs;
}

8. Consider Precision Needs

Choose appropriate precision for your use case:

Seconds: Most timestamps, expiration times
Milliseconds: Performance metrics, animations
Microseconds: High-frequency trading, scientific data

9. Handle Leap Seconds

Unix timestamps don't account for leap seconds. For most applications, this doesn't matter, but be aware if you need extreme precision.

10. Test Edge Cases

Always test with:

Daylight saving time transitions
Year boundaries
Different time zones
The Unix epoch (timestamp 0)
Future dates

Timestamp Best Practices for Web Development