date -u "+%Y-%m-%d %H:%M:%S"
2020-05-29 03:16:47
date -u "+%Y-%m-%d-%H-%M-%S"
2020-05-29-03-17-37
# unix timestamp (seconds)
date -u +%sdate -u "+%Y-%m-%d %H:%M:%S"
2020-05-29 03:16:47
date -u "+%Y-%m-%d-%H-%M-%S"
2020-05-29-03-17-37
# unix timestamp (seconds)
date -u +%s