Days to seconds – convert d to s

Convert days to seconds (d to s) to translate long timescales into exact numbers of seconds. Great for uptime calculations, countdowns, physics questions, astronomy and coding timers.

Open the interactive d → s converter:

Use main converter (d → s) or switch to s → d

From the homepage you can also step through hours, minutes and milliseconds for a full breakdown.

Quick reference: days to seconds

One day has 86,400 seconds. That means: seconds = days × 86,400. Some common values:

Days (d) Seconds (s)
0.5 d43,200 s
1 d86,400 s
2 d172,800 s
3 d259,200 s
7 d (1 week)604,800 s
14 d1,209,600 s
30 d2,592,000 s

Why convert days to seconds?

Days to seconds is useful when you:

Other time converters on this site

All time units on our homepage are linked with exact factors, so you can move cleanly between days, hours, minutes and seconds.

Page last updated: 4 December 2025.