EsriTimeDelta (arcpy.time)
Summary
The EsriTimeDelta class represents a duration, the difference between two dates or times.
Discussion
The EsriTimeDelta class is an alternative to the core Python datetime.timedelta and uses internal Esri time units for intervals that can't be handled by the core Python timedelta object (such as months, weeks, and so on).
The timeStepInterval property from the LayerTime and DataFrameTime classes return EsriTimeDelta objects.
Prior to the 10.1 release, the timeStepInterval property from the DataFrameTime class returned core Python datetime.timedelta objects.
Syntax
Parameter | Explanation | Data Type |
interval |
The interval of the EsriTimeDelta. | Double |
units | The units of the EsriTimeDelta. Valid units are milliseconds, seconds, minutes, hours, days, weeks, months, years, decades, and centuries. | String |
Properties
Property | Explanation | Data Type |
interval (Read Only) |
The interval of the EsriTimeDelta. | Double |
units (Read Only) | The units of the EsriTimeDelta. | String |
Code Sample
The following script accesses the time-step interval property of a time-enabled layer in a map document. The time-step interval is an EsriTimeDelta object. The script then prints EsriTimeDelta properties.
import arcpy
mxd = arcpy.mapping.MapDocument('C:/Project/Temperature.mxd')
df = arcpy.mapping.ListDataFrames(mxd, 'USA')[0]
lyr = arcpy.mapping.ListLayers(mxd,'temperature', df)[0]
tsi = lyr.time.timeStepInterval
print "Time Step Interval:", tsi
print "EsriTimeDelta interval:", tsi.interval
print "EsriTimeDelta units:", tsi.units
The following script uses the EsriTimeDelta object to iterate through twelve months starting from the current date.
import arcpy, datetime
time = datetime.datetime.now()
for delta in range(1, 13):
next_date = time + arcpy.time.EsriTimeDelta(1 * delta, "months")
print next_date
The following script shows how the EsriTimeDelta handles leap years. The script adds a month to January 31, 2008 and returns February 29, 2008.
import arcpy, datetime
time = datetime.datetime(2008, 1, 31)
for delta in range(0, 12):
next_date = time + arcpy.time.EsriTimeDelta(delta, "months")
print next_date
delta = delta + 1