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ee.Date.difference
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
會傳回兩個日期之間的差異，單位為指定的單位；結果為浮點值，並根據單位的平均長度計算。
| 用量 | 傳回 |
|---|
Date.difference(start, unit) | 浮點值 |
| 引數 | 類型 | 詳細資料 |
|---|
this：date | 日期 | |
start | 日期 | |
unit | 字串 | 可以是「year」、「month」、「week」、「day」、「hour」、「minute」或「second」。 |
範例
程式碼編輯器 (JavaScript)
// Demonstrates the ee.Date.difference method.
var DATE_1 = ee.Date('2020-01-01');
var DATE_2 = ee.Date('2020-01-15');
var diff_1 = DATE_2.difference(DATE_1, 'days');
var diff_2 = DATE_1.difference(DATE_2, 'weeks');
print('The difference between ',
DATE_2,
' relative to ',
DATE_1,
' is ',
diff_1,
' days.');
print('The difference between ',
DATE_1,
' relative to ',
DATE_2,
' is ',
diff_2,
' weeks.');
Python 設定
請參閱「
Python 環境」頁面，瞭解 Python API 和如何使用 geemap 進行互動式開發。
import ee
import geemap.core as geemap
Colab (Python)
DATE_1 = ee.Date('2020-01-01')
DATE_2 = ee.Date('2020-01-15')
# Format the dates as strings.
t1 = DATE_1.format('YYYY-MM-DD').getInfo()
t2 = DATE_2.format('YYYY-MM-DD').getInfo()
# Calculate the differences between dates.
diff_1 = DATE_2.difference(DATE_1, 'days').getInfo()
diff_2 = DATE_1.difference(DATE_2, 'weeks').getInfo()
print(f'The difference between {t2} relative to {t1} is {diff_1} days.')
print(f'The difference between {t1} relative to {t2} is {diff_2} weeks.')
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上次更新時間：2025-07-25 (世界標準時間)。
[null,null,["上次更新時間：2025-07-25 (世界標準時間)。"],[[["\u003cp\u003e\u003ccode\u003eDate.difference()\u003c/code\u003e calculates the difference between two dates, returning a floating-point number.\u003c/p\u003e\n"],["\u003cp\u003eThe difference is calculated based on the average length of the specified unit (e.g., 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second').\u003c/p\u003e\n"],["\u003cp\u003eThe function takes two \u003ccode\u003eee.Date\u003c/code\u003e objects as input, representing the start and end points for the calculation.\u003c/p\u003e\n"],["\u003cp\u003eThe result is relative to the first date and can be positive or negative depending on the order of the dates.\u003c/p\u003e\n"]]],["`Date.difference` calculates the difference between two dates, returning a floating-point number based on the average length of the specified unit. The function takes a `start` date and a `unit` string ('year', 'month', 'week', 'day', 'hour', 'minute', or 'second') as arguments. The output represents the difference in the chosen unit. Examples show calculating differences in days and weeks between two dates, showcasing both JavaScript and Python implementations.\n"],null,["# ee.Date.difference\n\nReturns the difference between two Dates in the specified units; the result is floating-point and based on the average length of the unit.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|--------------------------------|---------|\n| Date.difference`(start, unit)` | Float |\n\n| Argument | Type | Details |\n|--------------|--------|-----------------------------------------------------------------------|\n| this: `date` | Date | |\n| `start` | Date | |\n| `unit` | String | One of 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second'. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Demonstrates the ee.Date.difference method.\n\nvar DATE_1 = ee.Date('2020-01-01');\nvar DATE_2 = ee.Date('2020-01-15');\n\nvar diff_1 = DATE_2.difference(DATE_1, 'days');\nvar diff_2 = DATE_1.difference(DATE_2, 'weeks');\n\nprint('The difference between ',\n DATE_2,\n ' relative to ',\n DATE_1,\n ' is ',\n diff_1,\n ' days.');\n\nprint('The difference between ',\n DATE_1,\n ' relative to ',\n DATE_2,\n ' is ',\n diff_2,\n ' weeks.');\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\nDATE_1 = ee.Date('2020-01-01')\nDATE_2 = ee.Date('2020-01-15')\n\n# Format the dates as strings.\nt1 = DATE_1.format('YYYY-MM-DD').getInfo()\nt2 = DATE_2.format('YYYY-MM-DD').getInfo()\n\n# Calculate the differences between dates.\ndiff_1 = DATE_2.difference(DATE_1, 'days').getInfo()\ndiff_2 = DATE_1.difference(DATE_2, 'weeks').getInfo()\n\nprint(f'The difference between {t2} relative to {t1} is {diff_1} days.')\nprint(f'The difference between {t1} relative to {t2} is {diff_2} weeks.')\n```"]]
