How do I subtract the immediate value from Python and compare it to a fixed value of 120?

if sheet["A" + str(i)].value == a1.name:
rn = random.randint(1,100)
percent = sheet["B" + str(i)].value
level = sheet["C" + str(i)].value
cooltime = sheet["D" + str(i)].value
If datetime.datetime.now()-cooltime >= 120: # <- This is line 52.

import discord
from discord.ext import commands
import openpyxl
import random
import datetime
import os

bot = commands.Bot(command_prefix = '/')
global filename
filename = 'Enhanced.xlsx'

@bot.event
async def on_ready():
    print('The reinforcement bot has been activated.')

#Handle options to receive messages
@bot.command(pass_context=True)
async def hardening (ctx):
    a1 = ctx.message.author

    # Check the location of the executable file to ensure that the file location is the same as that of the executable file
    BASE_PATH = os.path.dirname(os.path.abspath(__file__))+"\\"
    # Create the first time if the file does not exist
    if os.path.isfile(BASE_PATH+filename) == False:
        newbook = openpyxl.Workbook()
        newbook.save(BASE_PATH+filename)
        newbook.close()
        newbook = None
        #Printing that you made the file
        print ("create reinforced file")

    print("File location:"+os.path.abspath(BASE_PATH+filename))

    book = openpyxl.load_workbook(BASE_PATH+filename)
    sheet = book.worksheets[0]
    i = 1
    # Variables to determine if you want to continue looking for Excel
    needLoop = True
    while needLoop:
        print ("Row No."+str(i)+"Checking...")
        print("User number: "+str(a1)")
        print("Excel User Number: %s"%sheet["A" + str(i).value)
        print("Excel probability: %s"%sheet["B" + str(i).value)
        print("Excel level: %s"%sheet["C" + str(i).value)
        print("Excel Last Time: %s"%sheet["D" + str(i).value)
        if sheet["A" + str(i)].value == a1.name:
            rn = random.randint(1,100)
            percent = sheet["B" + str(i)].value
            level = sheet["C" + str(i)].value
            cooltime = sheet["D" + str(i)].value
            dt = datetime.datetime.now()
            if dt - cooltime >= 120:
                if rn >= percent:
                    level = sheet["C" + str(i)].value + 1
                    percent = sheet["B" + str(i)].value / 3
                    sheet["C" + str(i)] = level
                    sheet["B" + str(i)] = percent
                    cooltime = datetime.datetime.now()
                    sheet["D" + str(i)].value = cooltime
                    book.save(filename)
                    ctx.sent(a1+" raised it to level"+str(level)+". Probability after hardening:"+str(percent))
                else:
                    level = sheet["C" + str(i)].value - 1
                    percent = sheet["B" + str(i)].value * 3
                    sheet["C" + str(i)] = level
                    sheet["B" + str(i)] = percent
                    cooltime = datetime.datetime.now()
                    sheet["D" + str(i)].value = cooltime
                    book.save(filename)
                    ctx.send(a1+" has gone down to"+str(level)+" level. Probability after hardening:"+str(percent))
            else:
                ctx.Send(a1+"nim"+str(cooltime)+" has a cool time left.")
        elif (sheet["A" + str(i)].value == None):
            #If there is no information in the excel, end it and add the current user's initial value
            sheet["A" + str(i)] = a1.name
            sheet["B" + str(i)] = 100
            sheet["C" + str(i)] = 1
            sheet["D" + str(i)] = datetime.datetime.now()
            i = i + 1
            print ("User Data Generation Completed")
    needLoop = False
    i = i + 1
    print ("End of execution of reinforcement")
    book.save(BASE_PATH+filename)
    # When it is possible to save, it is out of the 을
    book.close()
    ctx.send('User data generated successfully. Please reinforce it again.')

bot.run('bot_token') # <- It's actually a discode bot token. The bot token should not be leaked, so I kept it private like this. Please ignore me.