System Time
Get accurate system time information in multiple formats.
Quick Usage
Current Time (Local)
date # Human readable
date -Iseconds # ISO 8601 with seconds
date +%s # Unix timestamp
Current Time (UTC)
date -u # UTC human readable
date -u -Iseconds # UTC ISO 8601
date -u +%s # UTC Unix timestamp (same as local)
Specific Timezone
TZ=Asia/Shanghai date # Shanghai time
TZ=America/New_York date # New York time
TZ=Europe/London date # London time
Common Formats
| Format | Command | Example Output |
|---|---|---|
| ISO 8601 | date -Iseconds | 2024-03-11T16:30:00+08:00 |
| Unix timestamp | date +%s | 1710145800 |
| RFC 2822 | date -R | Mon, 11 Mar 2024 16:30:00 +0800 |
| Custom | date "+%Y-%m-%d %H:%M:%S" | 2024-03-11 16:30:00 |
Timezone Conversion
Convert from one timezone to another:
# Convert specific time from Shanghai to New York
TZ=America/New_York date -d "2024-03-11 16:30:00 CST"
# List available timezones
ls /usr/share/zoneinfo/
Python Alternative (for scripting)
from datetime import datetime, timezone
# Current UTC time
utc_now = datetime.now(timezone.utc)
print(utc_now.isoformat())
# Current local time
local_now = datetime.now()
print(local_now.isoformat())
# Unix timestamp
print(int(utc_now.timestamp()))
Notes
- Unix timestamp is always UTC (timezone-independent)
- ISO 8601 format includes timezone offset
- Use
timedatectlon Linux systems for system clock info