Those mirrors have to be replaced before dark.
5 seconds sound clip from the The Last Man on Earth (1964) movie soundboard.
You can hear this line at 00:14:54 in the Blu-ray version of the movie.
Quote context
[...]
- I'm out of gas. That means one more stop I'll have to make.
- I can get rid of them later. Right now, I'm out of gas.
- But I'll take only what I need. They've got to last.
- They can wait too. I've got my life to worry about.
- Those mirrors have to be replaced before dark.
- Square blocks to search. How many of them still exist?
- How long will I have to keep up this search?
- I haven't much time left. It'll be dark in an hour.
- And now 12 long hours before the sun will rise... and drive them back to darkness.
[...]