Describe the bug
After a new user was added to our slack, the Timezone Butler started displaying timezone conversions anytime he was tagged even when there was no time in the actual message. I believe that the character '0PM' appear in this user's ID.

To Reproduce
Steps to reproduce the behavior:

1. Go to any slack channel with Timezone Butler
2. Say '0PM'
3. Other users will see timezone conversions for the nonsensical 0PM.

Expected behavior
No Timezone Butler conversion should occur when XPM or XAM is found in a user's ID as part of a tag

Screenshots

Additional context
In the screenshot, the middle welcome message is from somebody in the same time zone and me, so there was no conversion.