Linux/date

Unix Timestamp: date +%s date +%u  # %u - day of week (1..7); 1 is Monday date +%w  # %w - day of week (0..6); 0 is Sunday
 * 1) %s     seconds since 1970-01-01 00:00:00 UTC

date +%Y-%m-%d-%H-%M-%S # 2016-06-18-07-59-40 date +%Y%m%d%H%M%S # 20160618075940