日付と時刻の計算機
日付の間隔、正確な年齢、営業日、タイムゾーン、Unix時刻、ISO週番号、日の出・日の入りを計算できます。
計算機 15 個 · 検証済みの例 87 件
適切な計算を見つける
- Hours worked when the clocks change
Use dates and a time zone to distinguish clock readings from elapsed time, including repeated hours and unpaid breaks.
- A deadline that skips weekends and holidays
Add or subtract working days, choose the weekend pattern and supply the holidays that apply to your calendar.
- A meeting that works across time zones
Convert the meeting's actual date and compare working-hour overlaps, including seasonal changes in the time difference.
日付
- 日付に日数を足す・引く
開始日から指定した日数、週数、月数、年数または営業日数だけ前後の日付を求め、曜日と暦日での移動日数を表示します。
- 年齢計算ツール
生年月日から任意の日付での正確な年齢を年月日で計算し、次の誕生日や月・週・日・時間単位の年齢も表示します。
- 日付間の日数計算ツール
2つの日付の間隔を日数、年月日、週、時間で計算します。週末と指定した祝日を除く営業日数にも対応します。
- Business days calculator: add working days to a date
The deadline N business days after or before a start date, skipping weekends and the holidays you list, with the calendar days it spans.
時間
- 指定日までのカウントダウン計算ツール
任意のタイムゾーンの日時までの残り、または経過した日・時・分・秒をリアルタイムで表示し、時刻変更も考慮します。
- Hours calculator: hours between two times and weekly timesheet
Calculate work hours, breaks and weekly timesheets. Use dates and a time zone for overnight shifts across daylight-saving changes and repeated hours.
- Military time converter (24-hour time)
Military time converter: 12-hour to 24-hour time and back, how it is spoken, time-zone letters with the Zulu equivalent, and a full-day chart.
- タイムゾーン変換・会議予定ツール
1つのタイムゾーンの時刻を最大12の別の地域の現地時刻に変換します。夏時間を適用し、会議の予定表も表示します。
- Unix timestamp converter
Unix timestamp converter: epoch seconds, milliseconds, microseconds or nanoseconds to an ISO 8601 UTC date and local time, and dates back to epoch time.
- Time calculator: add and subtract hours and minutes
Add and subtract hours, minutes and seconds from a list of durations, with the total as H:MM:SS, decimal hours, minutes and seconds.
カレンダー
- Calendar converter (Hijri, Hebrew, Persian, Julian)
Convert a Gregorian date to Hijri (Umm al-Qura and tabular), Hebrew, Persian, Indian national (Saka) and Julian dates, or a Julian date back.
- Day of the week calculator
Day of the week for any date, past or future: the weekday in the Gregorian calendar, worked through step by step with Zeller's congruence.
- Leap year checker
Leap year checker: whether a year has 366 days under the Gregorian rule, which test decides it, and the previous and next leap years.
- Week number and day of year
Week number for any date: ISO 8601 week and week-numbering year, US week number, day of the year, days left in the year and the quarter.
太陽と空
計算機の選び方：日付と時刻
Calendar dates or elapsed time?
A date difference counts calendar boundaries; elapsed hours compare instants. Choose the date tool for days between events, the age tool for completed years and months, and the hours tool for shifts or timesheets. Decide whether to include the first or last day. For a deadline, choose working days and supply the weekend pattern and holidays that apply to your organization. A holiday calendar from another region can produce a plausible but incorrect due date.
Use the event's date and time zone
Clock readings can repeat or disappear when daylight-saving time changes. Enter the actual dates and named time zone when you need elapsed time across such a change. A fixed UTC offset describes one offset, not a region's seasonal rules. Unix timestamps represent instants; confirm whether your source counts seconds or milliseconds. For recurring meetings, compare more than one date because different regions change their clocks on different schedules.
Hours across clock changes · Meeting planner · Unix timestamps