英和和英

in code

to decipher a code

to decipher a code

attach a code to

the code in force

at midnight

Evening sets in.

nighttime

at daybreak―at daylight

crack a code

at break of day―at peep of day

from the night

in the stilly night

on that night

to work at night

We keep watch by turns

We take turns in keeping watch.

deep into the night

Night comes on.

Night falls

to pass the night―spend the night

to pass the night

break a code

to decipher a code―decode a message

a dark night

a dark night

a dark night

during the night

during the previous night

to keep watch