Date & Time: `date` (GNU `coreutils`)

Recipes

date <+format>
    %% - '%'
    %H - hour (00-23)
    %I - hour (01-12)
    %M - minute (00-59)
    %S - second (00-59)
    %T - %H:%M:%S
    %R - %H:%M
    %y - year (00-99)
    %Y - year (0000-9999)
    %m - month (01-12)
    %d - day of month (01-31)
    %D - %m/%d/%y
    %u - day of week (1-7, 1=Monday)
    %w - day of week (0-6, 0=Sunday)
    %n - newline ('\n')
    %t - tab ('\t')

Date & Time Format

References