date                                    # Human readable
date -Iseconds                          # ISO 8601 with seconds
date +%s                                # Unix timestamp

date -u                                 # UTC human readable
date -u -Iseconds                       # UTC ISO 8601
date -u +%s                             # UTC Unix timestamp (same as local)

TZ=Asia/Shanghai date                   # Shanghai time
TZ=America/New_York date                # New York time
TZ=Europe/London date                   # London time

# 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/

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()))