Metatime is the concept, often portrayed on television or other media, that the protagonists have their own functional timeline irrespective of any timelines or changes occurring around them. However there is a limit to the metatime and it does start to get fuzzy around the edges when it used up:

• photos change or newspaper articles fade
• protagonists start losing memories or even fading from existence
• protagonists may even change and have different personalities or clothing

Metatime is recorded on the collective Playbook and belongs exclusively to the PCs. It has three statistics - Width, Length and Lag. There are additional bonuses you can add to your collective Playbook that will give you more utilities with Metatime as well (such as extending it temporarily to passengers on your Timeship).

• Width is the number of instances you can have at different times. With a Width of 2 you can have a group of PCs spread into two different times.
• Length is the subjective time allowed for the PCs to do their work before they become part of the timeline they're in. This is measured in Game Sessions for the players.
• Lag is the measurement of the speed of change between earlier times and later times. How fast a photo changes, or how quickly an NPC's memory is affected

If you exceed the Length, you accrue a completion point as well as suffering from various “time fixing itself” changes as the Grandfather sees fit.

This a list of official BBC media that uses these concepts as a part of the story:

• Any episode with more than one Doctor
  • Classic Series
    • The Three Doctors
    • The Five Doctors
    • The Two Doctors
  • New Series
    • Time Crash
    • The Day of the Doctor
    • Twice Upon a Time
• Any episode with more than one time period
  • Classic Series
  • New Series
    • The Girl in the Fireplace
    • A Christmas Carol
  • Big Finish Audios
    • The Legacy of Time - specifically the Split Infinitives story:
      the 7th Doctor is in the 80s and Ace is in the 70s and they’re both going after a gang of alien criminals and working with the same members of UNIT/Counter Measures. The Doctor has to wait for the humans to remember what Ace wants him to know or what happened at the time period Ace is in.