Return ISO 8601 datetime.now() in the given time zone

datetime-now.zsh

#!/bin/zsh
# Return ISO 8601 datetime.now() in the given time zone

# Ask user for timezone abbreviation
read "abbr?Enter timezone (e.g. jst, utc, est, pst): "
abbr="${abbr:l}"  # normalize to lowercase

# Map common abbreviations to IANA timezone names
case "$abbr" in
  jst) tz="Asia/Tokyo" ;;
  utc) tz="UTC" ;;
  est) tz="America/New_York" ;;
  pst) tz="America/Los_Angeles" ;;
  cet) tz="Europe/Paris" ;;
  *) echo "Unsupported timezone: $abbr"; exit 1 ;;
esac

# Print ISO 8601 datetime
python3 -c "
from datetime import datetime
import zoneinfo

dt = datetime.now(zoneinfo.ZoneInfo('$tz'))
print(dt.strftime('%Y-%m-%dT%H:%M:%S%z')[:-2] + ':' + dt.strftime('%z')[-2:])
"