ee.Date.difference

  • Date.difference() calculates the difference between two dates, returning a floating-point number.

  • The difference is calculated based on the average length of the specified unit (e.g., 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second').

  • The function takes two ee.Date objects as input, representing the start and end points for the calculation.

  • The result is relative to the first date and can be positive or negative depending on the order of the dates.

Returns the difference between two Dates in the specified units; the result is floating-point and based on the average length of the unit.

UsageReturns
Date.difference(start, unit)Float
ArgumentTypeDetails
this: dateDate
startDate
unitStringOne of 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second'.

Examples

Code Editor (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 setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

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.')