Your date might remind you of your time constraint (“But I thought you needed to be home at 8…”). People who are dating online actively will appreciate your planning for a bad date and like the fact that you are saying to them “this is a good date”.
If you would rather not let them in on your planning for the worst-date-scenario, just say that you’d prefer to cancel your previous plans and spend your evening with them.
One common reason to delay a first date is due to an attempt to learn more about the other person. I found the first few minutes of the first date are worth more than dozens of emails.
Another reason to delay would be if the person you are communicating with has expressed extreme reservations about meeting people from the internet.
Honestly, I have never felt comfortable talking on the phone for long periods of time (even to close friends) so I prefer to jump straight from the internet communication to meeting.
In general, my rule is an invitation to meet should come by the third email you send.
In contrast, many times the dates ended with coffee or lunch.
This approach is a cousin to the having-your-friend-call-you-and-faking-an-emergency act that some people think is so slick.
Actually meeting the person you are talking to is one of the most important steps to online dating.
That sounds amusing but many online daters dwell on internet communication overly long. They wanted me to get the show on the road and they were right to feel that way.