ISO 8601: Date and Time Representation
ISO 8601 is the international standard for representing dates and times. Learn about the various formats, time zones, durations, and intervals.
Current Time in ISO 8601
Basic Date Formats
Calendar Date
Extended format with separators:
Basic format without separators:
Week Date
Extended format:
Basic format:
Ordinal Date
Extended format:
Basic format:
Time Formats
Local Time
Extended format:
Basic format:
With fractions:
UTC Time
Coordinated Universal Time:
With fractions:
Time Zone Offset
With offset:
Basic format:
Combined Date and Time
Complete Date-Time Representations
Durations
Duration Format
Basic duration syntax:
Examples:
3 years, 6 months, 4 days, 12 hours, 30 minutes, 5 seconds
2 hours and 30 minutes
1 year, 2 months, 3 days, 4 hours, 5 minutes, 6 seconds
Week Duration
3 weeks
1 week and 2 days
Time Intervals
Start and End
From start of 2025 to end of 2025
Start and Duration
8-hour period starting at 9 AM UTC
Duration and End
1.5-hour period ending at 3:30 PM UTC
Recurring Time Expressions
Repeating Intervals
Repeat 5 times: 1-hour meetings starting at 9 AM UTC on Jan 1, 2025
Daily recurrence starting from Jan 1, 2025 (infinite repetition)
Monthly recurrence for 12 months starting from Jan 1, 2025
Quick Reference
Common Formats
Date
Time
DateTime UTC
DateTime with timezone
Format Components
YYYY - 4-digit year
MM - 2-digit month (01-12)
DD - 2-digit day (01-31)
hh - 2-digit hour (00-23)
mm - 2-digit minute (00-59)
ss - 2-digit second (00-59)
T - Date/time separator
Z - UTC indicator
±hh:mm - Timezone offset