diff --git a/CHANGELOG.md b/CHANGELOG.md
index 68ea976..31e7a3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
  * Allow setting a code block on a line that already has text (it will start a newline for the codeblock)
  * Retain indentation when tab is used to indent a line, unless enter is pressed twice or user deletes the indentation
  * Add missing strings (for English and French)
+ * Add 'Last Month' date range for timesheet reports
 
 # 0.7.5
 
diff --git a/bouquin/locales/en.json b/bouquin/locales/en.json
index 8c3fa54..c8784fd 100644
--- a/bouquin/locales/en.json
+++ b/bouquin/locales/en.json
@@ -217,6 +217,7 @@
     "date_range": "Date range",
     "custom_range": "Custom",
     "last_week": "Last week",
+    "last_month": "Last month",
     "this_week": "This week",
     "this_month": "This month",
     "this_year": "This year",
diff --git a/bouquin/locales/fr.json b/bouquin/locales/fr.json
index 4d304df..2b889d7 100644
--- a/bouquin/locales/fr.json
+++ b/bouquin/locales/fr.json
@@ -217,6 +217,7 @@
   "date_range": "Plage de dates",
   "custom_range": "Personnalisé",
   "last_week": "La semaine dernière",
+  "last_month": "Le mois dernier",
   "this_week": "Cette semaine",
   "this_month": "Ce mois-ci",
   "this_year": "Cette année",
diff --git a/bouquin/time_log.py b/bouquin/time_log.py
index b93e286..1e4b303 100644
--- a/bouquin/time_log.py
+++ b/bouquin/time_log.py
@@ -1055,6 +1055,7 @@ class TimeReportDialog(QDialog):
         self.range_preset.addItem(strings._("today"), "today")
         self.range_preset.addItem(strings._("last_week"), "last_week")
         self.range_preset.addItem(strings._("this_week"), "this_week")
+        self.range_preset.addItem(strings._("last_month"), "last_month")
         self.range_preset.addItem(strings._("this_month"), "this_month")
         self.range_preset.addItem(strings._("this_year"), "this_year")
         self.range_preset.currentIndexChanged.connect(self._on_range_preset_changed)
@@ -1214,6 +1215,12 @@ class TimeReportDialog(QDialog):
             start = start_of_this_week.addDays(-7)  # last week's Monday
             end = start_of_this_week.addDays(-1)  # last week's Sunday
 
+        elif preset == "last_month":
+            # Previous calendar month (full month)
+            start_of_this_month = QDate(today.year(), today.month(), 1)
+            start = start_of_this_month.addMonths(-1)
+            end = start_of_this_month.addDays(-1)
+
         elif preset == "this_month":
             start = QDate(today.year(), today.month(), 1)
             end = today