How do you convert days to hours?
Multiply the number of days by 24. For a contractual deadline, first check whether it runs in calendar days or working days: the conversion is the same, the starting point is not.
d = h ÷ 24
Common deadlines in days and hours
| 0.25 d | 6 h |
| 0.5 d | 12 h |
| 1 d | 24 h |
| 2 d | 48 h |
| 3 d | 72 h |
| 5 d (working week) | 120 h |
| 7 d | 168 h |
| 10 d | 240 h |
| 14 d | 336 h |
| 30 d | 720 h |
| 365 d | 8,760 h |
Show every value
- 1 d = 24 h
- 2 d = 48 h
- 3 d = 72 h
- 4 d = 96 h
- 5 d = 120 h
- 6 d = 144 h
- 7 d = 168 h
- 8 d = 192 h
- 9 d = 216 h
- 10 d = 240 h
- 11 d = 264 h
- 12 d = 288 h
- 13 d = 312 h
- 14 d = 336 h
- 15 d = 360 h
- 16 d = 384 h
- 17 d = 408 h
- 18 d = 432 h
- 19 d = 456 h
- 20 d = 480 h
- 21 d = 504 h
- 22 d = 528 h
- 23 d = 552 h
- 24 d = 576 h
- 25 d = 600 h
- 26 d = 624 h
- 27 d = 648 h
- 28 d = 672 h
- 29 d = 696 h
- 30 d = 720 h
- 31 d = 744 h
- 32 d = 768 h
- 33 d = 792 h
- 34 d = 816 h
- 35 d = 840 h
- 36 d = 864 h
- 37 d = 888 h
- 38 d = 912 h
- 39 d = 936 h
- 40 d = 960 h
- 41 d = 984 h
- 42 d = 1,008 h
- 43 d = 1,032 h
- 44 d = 1,056 h
- 45 d = 1,080 h
- 46 d = 1,104 h
- 47 d = 1,128 h
- 48 d = 1,152 h
- 49 d = 1,176 h
- 50 d = 1,200 h
- 51 d = 1,224 h
- 52 d = 1,248 h
- 53 d = 1,272 h
- 54 d = 1,296 h
- 55 d = 1,320 h
- 56 d = 1,344 h
- 57 d = 1,368 h
- 58 d = 1,392 h
- 59 d = 1,416 h
- 60 d = 1,440 h
- 61 d = 1,464 h
- 62 d = 1,488 h
- 63 d = 1,512 h
- 64 d = 1,536 h
- 65 d = 1,560 h
- 66 d = 1,584 h
- 67 d = 1,608 h
- 68 d = 1,632 h
- 69 d = 1,656 h
- 70 d = 1,680 h
- 71 d = 1,704 h
- 72 d = 1,728 h
- 73 d = 1,752 h
- 74 d = 1,776 h
- 75 d = 1,800 h
- 76 d = 1,824 h
- 77 d = 1,848 h
- 78 d = 1,872 h
- 79 d = 1,896 h
- 80 d = 1,920 h
- 81 d = 1,944 h
- 82 d = 1,968 h
- 83 d = 1,992 h
- 84 d = 2,016 h
- 85 d = 2,040 h
- 86 d = 2,064 h
- 87 d = 2,088 h
- 88 d = 2,112 h
- 89 d = 2,136 h
- 90 d = 2,160 h
- 91 d = 2,184 h
- 92 d = 2,208 h
- 93 d = 2,232 h
- 94 d = 2,256 h
- 95 d = 2,280 h
- 96 d = 2,304 h
- 97 d = 2,328 h
- 98 d = 2,352 h
- 99 d = 2,376 h
- 100 d = 2,400 h
- 125 d = 3,000 h
- 150 d = 3,600 h
- 175 d = 4,200 h
- 200 d = 4,800 h
- 225 d = 5,400 h
- 250 d = 6,000 h
- 275 d = 6,600 h
- 300 d = 7,200 h
- 325 d = 7,800 h
- 350 d = 8,400 h
- 375 d = 9,000 h
- 400 d = 9,600 h
- 425 d = 10,200 h
- 450 d = 10,800 h
- 475 d = 11,400 h
- 500 d = 12,000 h
- 550 d = 13,200 h
- 600 d = 14,400 h
- 650 d = 15,600 h
- 700 d = 16,800 h
- 750 d = 18,000 h
- 800 d = 19,200 h
- 850 d = 20,400 h
- 900 d = 21,600 h
- 950 d = 22,800 h
- 1,000 d = 24,000 h
- 1,500 d = 36,000 h
- 2,000 d = 48,000 h
- 2,500 d = 60,000 h
- 3,000 d = 72,000 h
- 3,500 d = 84,000 h
- 4,000 d = 96,000 h
- 4,500 d = 108,000 h
- 5,000 d = 120,000 h
- 5,500 d = 132,000 h
- 6,000 d = 144,000 h
- 6,500 d = 156,000 h
- 7,000 d = 168,000 h
- 7,500 d = 180,000 h
- 8,000 d = 192,000 h
- 8,500 d = 204,000 h
- 9,000 d = 216,000 h
- 9,500 d = 228,000 h
- 10,000 d = 240,000 h
The day is exactly 86,400 seconds by convention, that is 24 hours of 60 minutes. The sidereal day, the true length of one rotation of the Earth relative to the stars, runs about 23 h 56 min 4 s: those four minutes come from the Earth moving along its orbit during that rotation. Methodology & sources.
Frequently asked questions
Is a day always 24 hours?
As a unit of duration, yes, always. As a calendar day, no: the day the clocks go forward holds 23 hours and the day they go back holds 25. Any automated job that adds 86,400 seconds to a date drifts by an hour on those two days.
How many hours in a month?
Between 672 and 744 depending on the month, that is 28 to 31 days times 24. The Gregorian average is 730.5 hours. Monthly billing by the hour should always state which of those figures it uses.
What does a 48-hour deadline mean?
Two full days from the stated moment, not two working days. Where the wording is vague in a contract, the count in hours is what settles it: 48 hours from a Friday 5 pm lands on Sunday 5 pm.
Why is the sidereal day shorter?
Because between two passages of the Sun across the meridian, the Earth has also moved along its orbit and has to turn a little further to catch up. The mean solar day, the one our clocks keep, therefore runs about four minutes longer than the sidereal day.
Why does the figure of 8,760 hours turn up everywhere?
Because it is the length of a common year, 365 × 24, and it serves as the denominator of a great many calculations. A 99.9 % availability guarantee allows 8.76 hours of downtime a year; at 99.99 % it leaves only 53 minutes. A leap year runs to 8,784 hours, and the mean Gregorian year to 8,766.