GNU date accepts natural-language deltas: "+1 day", "-3 weeks", "now + 2 hours". Combine with -d to compute against any reference date.
Bash
# Tomorrow / yesterday
date -d "tomorrow" +%F # 2025-03-13
date -d "yesterday" +%F # 2025-03-11
# N units from now
date -d "+7 days" +%F # one week from today
date -d "-2 weeks" +%F # two weeks ago
date -d "+3 months" +%F # three months from today
# From a specific date
date -d "2025-01-01 +30 days" +%F # 2025-01-31
# Same with a Unix timestamp result
date -d "2025-01-01 +30 days" +%s
# macOS / BSD date — different syntax (uses -v)
date -v +7d +%F # 7 days from now
date -v -1m +%F # 1 month agoSave your own code snippets
Create a free account and build your private vault. Share publicly whenever you want.