Related Clues:
- Long periods
- String of periods
- ... and another
- Very, very long time
- Waiting time at the motor vehicle bureau, seemingly
- Considerable stretch
- Forever, facetiously
- Stretches of history
- 1 billion years
- 365 billion days, astronomically
- Interminable stretch
- Almost eternity
- Longish span of time
- Millennia on end
- Geological span