[cheryl j (OP)]

Every now and then when I am reading someone's texts, there will be one that makes no conversational sense, and when I look at the date, it was actually sent several months ago from that person. Is this my phone showing some old deleted text, or one that was never successfully sent from their's, or was it bouncing around in space all that time?

[Spacetectonics]

Time travel
Sometimes when the cell is off for some reasons, date&time  mix up! I have experience sort of stuff like that,although it could be the service provider server" time as well!
I used to wake up by my phone  alarm,but I gave it up as I have noticed time changes sometimes (specially around midnight!!)

[graham.d]

Text does not get high priority and can get held up. This may be because the receiving phone is off or out of range for example, or can be because lines are busy with high priority traffic like voice calls. If this happens the message has to be stored until the route is open again. It can happen that this does not get resent for some time. I have never heard of this delay being for months though, but it can certainly be days. It will depend on the network and where you are in the world.

[krool1969]

I've had this happen too. Never by months, but sometimes by hours. I always figured it was sent to Pluto by mistake and whoever got it on Pluto sent in back out of kindness. Way to pay the Plutonians back for their kindness! "Demoting" their home to a "Dwarf Planet".