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wk
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What is a week?

The 7-day cycle used by all major calendars

Definition

The week equals 7 days — an invention of the ancient Babylonians linked to the 7 classical planetary bodies visible to the naked eye. The 7-day week is nearly universal today, used by all major calendar systems.

Common uses

  • Weekly schedules, pay cycles, delivery windows
  • Pregnancy tracking (measured in weeks)
  • Project management sprints

🌍 Real-world scale

UK workweek: Mon–Fri. US payroll cycle often biweekly. Pregnancy duration: 40 weeks.

Convert from weeks

9 conversions
Week to Second1 wk = 604,800 sWeek to Millisecond1 wk = 604,800,000 msWeek to Minute1 wk = 10,080 minWeek to Hour1 wk = 168 hWeek to Day1 wk = 7 dWeek to Month1 wk = 0.23 moWeek to Year1 wk = 0.01916 yrWeek to Decade1 wk = 0.001916 decWeek to Century1 wk = 0.0001916 c

Convert to weeks

9 conversions
Second to Week1 s = 1.6534e-6 wkMillisecond to Week1 ms = 1.6534e-9 wkMinute to Week1 min = 9.9206e-5 wkHour to Week1 h = 0.005952 wkDay to Week1 d = 0.1429 wkMonth to Week1 mo = 4.34812 wkYear to Week1 yr = 52.1786 wkDecade to Week1 dec = 521.786 wkCentury to Week1 c = 5,217.86 wk

Tips

  • 1 week = 7 days = 168 hours.
  • ISO 8601 week numbering standardises "Week 01 of Year" internationally.
  • Some cultures start week on Sunday, others on Monday — check locale.

Common mistakes

  • Assuming week starts on Sunday in Europe — most of Europe starts Monday.
  • Mixing fiscal weeks (e.g. 4-4-5 accounting) with calendar weeks.
  • Using "week" in science without specifying Julian or Gregorian basis — rarely matters but can.

FAQ about the week

What is a week?
The week equals 7 days — an invention of the ancient Babylonians linked to the 7 classical planetary bodies visible to the naked eye. The 7-day week is nearly universal today, used by all major calendar systems.
Where is the week used?
The week is commonly used for: Weekly schedules, pay cycles, delivery windows; Pregnancy tracking (measured in weeks); Project management sprints.
What is an example of a week in real life?
UK workweek: Mon–Fri. US payroll cycle often biweekly. Pregnancy duration: 40 weeks.
What category does the week belong to?
The week is a unit of time, part of the 10-unit time category on UnitConv.
How accurate are week conversions?
All conversion factors follow NIST and BIPM international standards to 8 significant figures — the highest practical accuracy.
Explore all 10 time units and their conversions.⏱️ Time hub →