Major - P3 $dateAdd/$dateSubtract expressions do not detect an overflow for certain 'amount' values. A result is undefined in such cases. An example of an expression that overflows:
{"$dateAdd":
{"startDate" : Timestamp(0, 4294967295),
"unit" : "month",
"amount" : {$multiply: [NumberLong("314159265358979383")]},
"timezone" : "+1187" }};