Background info: I am attempting to create a very slow world border increase (+1 block per hour) that will increase to a very large area (10000 block diameter), so my timeInSeconds value I want to use are very large (36000000 for the math above).
Extra info: I have observed four distinct results from various timeInSeconds values. These results have been observed in both survival and creative modes on the PC version. This bug occurs with both the set and add functions of the world border. The sizeInBlocks value does not appear to be a factor with this bug. The previous location of the world border does not appear to be a factor with this bug either.
Results #2 and #3 are the bug I want to report.
Bug details:
Result #1) Between the values of 0 and 2147483, the world border moves incrementally at the appropriate rate and displays the appropriate message that corresponds to a border moving incrementally. (Everything works great)
Result #2) Between the values of 2147484 and 4294967, the world border moves instantly and displays a message that corresponds to a world border moving instantly (as if no value was entered in the timeInSeconds)
Result #3) Between the values of 4294968 and 45097156, the world border moves incrementally at the incorrect rate and displays the appropriate message that corresponds to a border moving incrementally, however, the value displayed does not match the value entered by me.
Result #2 repeats for values between 45097157 and 999999999.
Result #4) Values 1000000000 and above return a message "[Value entered] is not a valid number" (Not saying this is a bug, but perhaps it is)