Welcome to the forum...
Make sure the calendar you placed it on is one you are still subscribed to, and that calendar is "showing" (checkmark next to it- far left column- "subscribed calendars.") Can't you just go to that date and time in any one of the three views and see it?
Did it disappear when you saved it, or is something else happening?
"A soft answer turneth away wrath" works great on LDSTech forum boards!