What you experience is a glitch with the operating system. Some iPad/iPhone users get these emails, most don't. They could disappear after some time. If that's not the case, try resetting (rebooting) your device. This won't remove data or settings from your iPad.
Reset: press and hold Home and Power button until the Apple logo appears. Release both and let the iPad power up on it's own.
Nobody knows exactly why it happens but it relates to Unix Time which is a system for describing instants in time.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.