title: Discord.py bot using datetime returns this (TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'int')
body: <p>I'm trying to make a Discord bot that counts the time elapsed since somebody said "word" but my current method returns the above error. I am very new to python and discord.py so please bear with me.</p>
  
  <p>My search turned up <a href="https://stackoverflow.com/a/54274151/11861092">this</a> but even with knowing why the error occurred, I'm not sure of any other way to go about this.</p>
  
  <pre class="lang-py prettyprint-override"><code>import discord, os, re
  import datetime
  import asyncio
  from discord.ext import commands
  from datetime import datetime
  
  token = ('')
  bot = commands.Bot(command_prefix='!')
  client = discord.client
  start = 0
  end = 0
  elapsed = 0
  elapsedstr = str
  
  @bot.event
  async def on_ready():
      print("Bot is live")
  
  @bot.event
  async def on_message(message):
      if 'word' in message.content:
        global start
        start = datetime.datetime.now()
      await bot.process_commands(message)
  
  
  @bot.command()
  async def lastsaid(ctx):
      print('running lastsaid')
      global end
      global elapsed
      end = datetime.now()
      elapsed = end - start
      elapsedstr = datetime.now.strftime('%H:%M:%S', datetime.gmtime(elapsed))
      await ctx.send(('It has been ' + elapsedstr + ' since someone said the word!'))
      print('sent ls')
  
  if __name__ == '__main__':
      bot.run(token)
  </code></pre>
  
  <p>How would I go about calculating the time elapsed without this error?</p>