Now which 1500 is that? Unless it is truncating the "29" in output only, did it accept it for today, not tomorrow?
What you see in response to lodgement is the FPL message matching your flight. The current FPL message format, which is what is passed on to other ANSPs if you fly international, has no provision for plans in advance of 24 hours. It simply cannot show the date. I guess that AsA currently store the message until it is within the 24-hour window before injecting it into their live processing. BTW, The "new" NAIPS displays the same message and emails you a copy.
The new FPL message has provision for a date-of-flight that uses an Item 18 DOF/ tag in the submitted plan to indicate the date in combo with the existing ETD (renamed estimated off-blocks time EOBT). A sample message will look like:
Code:
(FPL-QFA557-IS
-A332/H-SDE2E3FGHIJ2J4J5M1RWYZ/B1D1L
-YSSY0210
-M081F400 DCT KAT A576 PKS J141 KG Q41 HAMTN Q158 PH DCT
-PBN/A1B1D1L1 NAV/GPSRNAV TCAS DOF/121031 REG/VHEBH SEL/FGAK PER/C RIF/SEVSI J141 FRT N640 AD YPAD
(I am not an expert, that is just the info AsA provided.)
AsA still have to implement a store-and-forward system because some parties (e.g. the FAA) have decided they still will not accept plans in advance of 24 hours.