ee.Filter.calendarRange

AI-generated Key Takeaways

• The ee.Filter.calendarRange function returns a filter for timestamps within a calendar field range.

• Calendar fields like month and day are 1-based, and times are assumed to be in UTC.

• A wrapping range is supported where the end value is less than the start value.

• The preferred methods for filtering by whole years and day of year are ee.Filter.date and ee.Filter.dayOfYear, respectively, due to performance.

Returns a filter that passes if the object's timestamp falls within the given range of a calendar field. The month, day_of_year, day_of_month, and day_of_week are 1-based. Times are assumed to be in UTC. Weeks are assumed to begin on Monday as day 1. If end < start then this tests for value >= start OR value <= end, to allow for wrapping.

Usage	Returns
ee.Filter.calendarRange(start, end, field)	Filter

Argument	Type	Details
start	Integer	The start of the desired calendar field, inclusive.
end	Integer, default: null	The end of the desired calendar field, inclusive. Defaults to the same value as start.
field	String, default: "day_of_year"	The calendar field to filter over. Options are: `year`, `month`, `hour`, `minute`, `day_of_year`, `day_of_month`, and `day_of_week`.

Examples

Code Editor (JavaScript)

// A Sentinel-2 surface reflectance image collection intersecting the peak of
// Mount Shasta, California, USA.
var ic = ee.ImageCollection('COPERNICUS/S2_SR')
             .filterBounds(ee.Geometry.Point(-122.196, 41.411));

print('Images for a month range (June-August)',
      ic.filter(ee.Filter.calendarRange(6, 8, 'month')));

print('A start value greater than end value is valid (Dec-Feb)',
      ic.filter(ee.Filter.calendarRange(12, 2, 'month')));

// This example uses the 'year' field value. Note that ee.Filter.date is the
// preferred method when filtering by whole years, as it is much faster.
print('Images for a year range (2020-2021)',
      ic.filter(ee.Filter.calendarRange(2020, 2021, 'year')));

// This example uses the 'day_of_year' field value. Note that
// ee.Filter.dayOfYear is the preferred method for filtering by DOY.
// The ee.Date.getRelative function is used to identify DOY from an ee.Date
// object for a representative year. Be mindful of leap years when filtering
// by DOY.
var startDoy = ee.Date('2000-06-01').getRelative('day', 'year');
var endDoy = ee.Date('2000-06-15').getRelative('day', 'year');
print('start DOY =', startDoy,
      'end DOY =', endDoy,
      'Images for a day-of-year range',
      ic.filter(ee.Filter.calendarRange(startDoy, endDoy, 'day_of_year')));

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)

# A Sentinel-2 surface reflectance image collection intersecting the peak of
# Mount Shasta, California, USA.
ic = ee.ImageCollection('COPERNICUS/S2_SR').filterBounds(
    ee.Geometry.Point(-122.196, 41.411))

print('Images for a month range (June-August):',
      ic.filter(ee.Filter.calendarRange(6, 8, 'month')).getInfo())

print('A start value greater than end value is valid (Dec-Feb):',
      ic.filter(ee.Filter.calendarRange(12, 2, 'month')).size().getInfo())

# This example uses the 'year' field value. Note that ee.Filter.date is the
# preferred method when filtering by whole years, as it is much faster.
print('Images for a year range (2020-2021):',
      ic.filter(ee.Filter.calendarRange(2020, 2021, 'year')).size().getInfo())

# This example uses the 'day_of_year' field value. Note that
# ee.Filter.dayOfYear is the preferred method for filtering by DOY.
# The ee.Date.getRelative function is used to identify DOY from an ee.Date
# object for a representative year. Be mindful of leap years when filtering
# by DOY.
start_doy = ee.Date('2000-06-01').getRelative('day', 'year')
end_doy = ee.Date('2000-06-15').getRelative('day', 'year')
print('start DOY =', start_doy.getInfo(), 'end DOY =', end_doy.getInfo())
print(
    'Images for a day-of-year range:',
    ic.filter(ee.Filter.calendarRange(start_doy, end_doy, 'day_of_year'))
    .getInfo()
)