Arcmap uses python to process date fields

1. Processing date

1. Define the function

def s(id):
    if(id >= 245):
       date=datetime.datetime.strptime('2018-01-01 00:00:00','%Y-%m-%d %H:%M:%S')
       delta = datetime.timedelta(days = id+2 )
       endTime = date+delta
       return endTime
    else:
       date=datetime.datetime.strptime('2018-01-01 00:00:00','%Y-%m-%d %H:%M:%S')
       delta = datetime.timedelta(days = id-1 )
       endTime = date+delta
       return endTime
2、调用函数

s( !OBJECTID! )

Two, processing string

1. Define the function

def s(id):
  return id[0:5]
2. Call the function

s(!DISSOLVEID!)