On 17-18 March 2016 the Senate sat without a break for 28 hours 56 minutes to debate the Commonwealth Electoral Amendment Bill 2016. It is believed this is the longest continuous sitting of the Senate.
The longest continuous sitting of the House of Representatives is 57 hours and 30 minutes, and took place from Thursday 16 to Saturday 18 November 1905. The members took a break at midnight on the Saturday but returned on Monday 20 November 1905 to continue their debate.
Most long sittings are broken by suspensions—breaks—to allow the members of parliament to rest, have a meal or sleep.
For example, the overall longest sitting of the House was from 18 to 25 January 1918, a period of 175 hours and 22 minutes. A suspension of the sitting from 3.09 am on 19 January until 3 pm on 25 January meant the members were not in the chamber for the whole 175 hours!