Time dilation fields are areas in which time moves faster or slower than in the surrounding space, depending on the configuration of the device generating it. The Ancients and Asgard are both races that utilize time dilation devices.
- The Asgard first known use of a time dilation device was to trap the Replicators in a field with a .16 light year radius. Time inside of the field was programed to be 10,000 times slower than surrounding space - one minute inside was equivalent to several years outside. However, the Replicators modified the device so that time progressed much quicker inside the field, giving them enough time to absorb all of the materials on the entire planet's surface. SG-1 was dispatched to fix the problem. Then about 1 year later, the Replicators modified the time dilation device to escape the gravity of the Black hole that the Asgard had created from what was once Hala's sun. (SG1: "Unnatural Selection", "New Order, Part 1")
- In 2006, Lt. Colonel John Sheppard was once trapped in a time dilation field which caused a six months to pass within the field while only a few hours had passed outside. The remaining members of his team then entered the field with the intent to shut it down. However, they were stopped by the ascended villagers inside the field, who canceled out the fields effects until the team had left. (SGA: "Epiphany")
- A time dilation field was one of the tests Morgan Le Fay set up to test if people were worthy of possessing the Sangraal. Time inside the field passed much slower than time outside. However, there was a path of "real time" winding its way through the field, creating a maze.(SG1: "The Quest, Part 1")
- The Asgard computer core is also equipped with a time dilation device. This was used to protect SG-1 and Major General Henry Landry from an Ori weapons. While only fractions of a second had passed outside of the field, fifty to sixty years progressed inside. Lt. Colonel Samantha Carter eventually managed to reverse time inside the field, allowing them to escape the Ori beam that was traveling towards them. Teal'c was placed inside a field so that he was not effected by the time reset, thus allowing him to alter the timeline so that the team could escape. However, this made him remain old. (SG1: "Unending")