diff --git a/test/residual_test/residual_test.py b/test/residual_test/residual_test.py
index bae9bc5a91e4e9a817a8940b8318f07302665498..8b156125bd3696e86b1a2dd60df4674ddff6ab62 100644
--- a/test/residual_test/residual_test.py
+++ b/test/residual_test/residual_test.py
@@ -55,15 +55,21 @@ def get_json_readings(filename: str):
     return readings
 
 
-def get_spreadsheet_absolutes(path):
+def get_spreadsheet_absolutes(
+    observatory: str, starttime: UTCDateTime, endtime: UTCDateTime, path
+):
     """
     Tests functionality of SpreadsheetAbsolutesFactory and recalculation of absolutes
     """
     # establish SpreadsheetAbsolutesFactory for reading test data from Excel
-    saf = SpreadsheetAbsolutesFactory()
+    saf = SpreadsheetAbsolutesFactory(base_directory=path)
     # Read spreadsheet containing test data
-    reading = saf.parse_spreadsheet(path=path)
-    return reading
+    readings = saf.get_readings(
+        observatory=observatory,
+        starttime=UTCDateTime(starttime),
+        endtime=UTCDateTime(endtime),
+    )
+    return readings
 
 
 def get_spreadsheet_directory_readings(path, observatory, starttime, endtime):
@@ -100,11 +106,17 @@ def test_DED_20140952332():
     Tests calculations for measurements in units of DMS.
     """
     # gather absolute from DED test data and recalculate
-    reading = get_spreadsheet_absolutes(path="etc/residual/DED-20140952332.xlsm")
-    # test results with original spreadsheet values
-    assert_readings_equal(
-        expected=reading, actual=calculate(reading=reading), decimal=2
+    readings = get_spreadsheet_absolutes(
+        observatory="DED",
+        starttime="2014-01-01",
+        endtime="2014-05-01",
+        path="etc/residual/DED-20140952332.xlsm",
     )
+    # test results with original spreadsheet values
+    for reading in readings:
+        assert_readings_equal(
+            expected=reading, actual=calculate(reading=reading), decimal=2
+        )
 
 
 def test_BRW_20133650000():
@@ -114,13 +126,19 @@ def test_BRW_20133650000():
     Tests calculations for measurements in units of DM.
     """
     # gather absolute from DED test data and recalculate
-    reading = get_spreadsheet_absolutes(path="etc/residual/BRW-20133650000.xlsm")
-    # test results with original spreadsheet values
-    assert_readings_equal(
-        expected=reading,
-        actual=calculate(reading=reading),
-        decimal=1,  # change due to no longer rounding
+    readings = get_spreadsheet_absolutes(
+        observatory="BRW",
+        starttime="2013-01-01",
+        endtime="2013-12-31",
+        path="etc/residual/BRW-20133650000.xlsm",
     )
+    # test results with original spreadsheet values
+    for reading in readings:
+        assert_readings_equal(
+            expected=reading,
+            actual=calculate(reading=reading),
+            decimal=1,  # change due to no longer rounding
+        )
 
 
 def test_BOU_20190702():