Day (d)
Exactly 86 400 seconds (24 hours). Leap seconds are not considered.
What is a day?
- Symbol
- d
- Quantity
- Time
- Unit system
- SI-accepted
- Definition
- Exactly 86 400 seconds (24 hours). Leap seconds are not considered.
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used for calendars, deadlines and durations. Here a day is exactly 86,400 seconds.
Day in other time units
- 1 d = 86400000000000 nsNanosecond
- 1 d = 86400000000 µsMicrosecond
- 1 d = 86400000 msMillisecond
- 1 d = 86400 sSecond
- 1 d = 1440 minMinute
- 1 d = 24 hDay to Hour converter
- 1 d ≈ 0.1428571429 wkDay to Week converter
- 1 d ≈ 0.002737850787 yrDay to Year (Julian) converter
Day quick reference
| Day | Hour | Week | Year (Julian) |
|---|---|---|---|
| 1 d | = 24 h | ≈ 0.1428571429 wk | ≈ 0.002737850787 yr |
| 10 d | = 240 h | ≈ 1.428571429 wk | ≈ 0.02737850787 yr |
| 100 d | = 2400 h | ≈ 14.28571429 wk | ≈ 0.2737850787 yr |
| 1000 d | = 24000 h | ≈ 142.8571429 wk | ≈ 2.737850787 yr |
Where the day fits
The next smaller time unit is the hour (h). 1 d = 24 h, and 1 h ≈ 0.04166666667 d.
The next larger time unit is the week (wk). 1 d ≈ 0.1428571429 wk, and 1 wk = 7 d.
Frequently asked questions
- How many hours are in one day?
- One day = 24 h (hours).
- How many weeks are in one day?
- One day ≈ 0.1428571429 wk (weeks).
- How many Julian years are in one day?
- One day ≈ 0.002737850787 yr (Julian years).