Linky: https://forum-en.guildwars2.com/forum/game/gw2/Guild-Mission-Reset-Time-Changed
"In order to accommodate development and hosting of Guild Wars 2 raids, we will be changing the time that guild mission resets take place each week. Starting Monday, October 5, 2015, guild mission resets will take place at 12:30 AM Pacific time each Monday.
Note: In order to make this adjustment there will be no reset on Saturday evening, October 3. Instead, that week’s guild mission period will be extended slightly to allow for this update. Subsequently, guild mission resets will occur each Monday morning, at 12:30 AM Pacific time."
Just to let you all know. :)