parser.add_argument('-t','--time',type=str,default=None,help='Length of time to simulate, e.g., 123, 123s, 27m, 3h, 7d')
parser.add_argument('--system',type=str,default='frontier',help='System config to use')
choices=['prescribed','poisson']
parser.add_argument('--arrival',default=choices[0],type=str,choices=choices,help=f'Modify arrival distribution ({choices[1]}) or use the original submit times ({choices[0]})')