Slow Message Services

Got a sms from a friend at 11:30 am this morning. This was followed immediately by another from him time stamped 11:40 am. The first sms was to remind me of our lunch appointment at 12 and the second was to inform me that he was already at the Soup Spoon.

Nothing unusual about that except that my appointment was yesterday and the sms were sent yesterday.

What the heck happened? 24 hours for an sms to reach me?