Parliament House has tweeted on the exact timing of its dissolution:
The Official Secretary to the Governor General will read out a proclamation dissolving the HOR at the front of APH at 5:29 pm. (1/3)
— Australian House of Representatives (@AboutTheHouse) August 5, 2013
So if the minister’s office are being arses you:
a) have to do what they say for the rest of today
b) can maybe get away with sandbagging until 5.30pm