diff --git a/lib/circuit_breaker.sh b/lib/circuit_breaker.sh
index e681cae..3e11460 100644
--- a/lib/circuit_breaker.sh
+++ b/lib/circuit_breaker.sh
@@ -3,6 +3,9 @@
 # Prevents runaway token consumption by detecting stagnation
 # Based on Michael Nygard's "Release It!" pattern
 
+# Source date utilities for cross-platform compatibility
+source "$(dirname "${BASH_SOURCE[0]}")/date_utils.sh"
+
 # Circuit Breaker States
 CB_STATE_CLOSED="CLOSED"        # Normal operation, progress detected
 CB_STATE_HALF_OPEN="HALF_OPEN"  # Monitoring mode, checking for recovery
@@ -36,7 +39,7 @@ init_circuit_breaker() {
         cat > "$CB_STATE_FILE" << EOF
 {
     "state": "$CB_STATE_CLOSED",
-    "last_change": "$(date -Iseconds)",
+    "last_change": "$(get_iso_timestamp)",
     "consecutive_no_progress": 0,
     "consecutive_same_error": 0,
     "last_progress_loop": 0,
@@ -164,7 +167,7 @@ record_loop_result() {
     cat > "$CB_STATE_FILE" << EOF
 {
     "state": "$new_state",
-    "last_change": "$(date -Iseconds)",
+    "last_change": "$(get_iso_timestamp)",
     "consecutive_no_progress": $consecutive_no_progress,
     "consecutive_same_error": $consecutive_same_error,
     "last_progress_loop": $last_progress_loop,
@@ -196,7 +199,7 @@ log_circuit_transition() {
 
     local history=$(cat "$CB_HISTORY_FILE")
     local transition="{
-        \"timestamp\": \"$(date -Iseconds)\",
+        \"timestamp\": \"$(get_iso_timestamp)\",
         \"loop\": $loop_number,
         \"from_state\": \"$from_state\",
         \"to_state\": \"$to_state\",
@@ -272,7 +275,7 @@ reset_circuit_breaker() {
     cat > "$CB_STATE_FILE" << EOF
 {
     "state": "$CB_STATE_CLOSED",
-    "last_change": "$(date -Iseconds)",
+    "last_change": "$(get_iso_timestamp)",
     "consecutive_no_progress": 0,
     "consecutive_same_error": 0,
     "last_progress_loop": 0,
diff --git a/lib/date_utils.sh b/lib/date_utils.sh
new file mode 100644
index 0000000..1e92b3b
--- /dev/null
+++ b/lib/date_utils.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# date_utils.sh - Cross-platform date utility functions
+# Provides consistent date formatting and arithmetic across GNU (Linux) and BSD (macOS) systems
+
+# Get current timestamp in ISO 8601 format with seconds precision
+# Returns: YYYY-MM-DDTHH:MM:SS+00:00 format
+get_iso_timestamp() {
+    local os_type
+    os_type=$(uname)
+
+    if [[ "$os_type" == "Darwin" ]]; then
+        # macOS (BSD date)
+        # Use manual formatting and add colon to timezone offset
+        date -u +"%Y-%m-%dT%H:%M:%S%z" | sed 's/\(..\)$/:\1/'
+    else
+        # Linux (GNU date) - use -u flag for UTC
+        date -u -Iseconds
+    fi
+}
+
+# Get time component (HH:MM:SS) for one hour from now
+# Returns: HH:MM:SS format
+get_next_hour_time() {
+    local os_type
+    os_type=$(uname)
+
+    if [[ "$os_type" == "Darwin" ]]; then
+        # macOS (BSD date) - use -v flag for date arithmetic
+        date -v+1H '+%H:%M:%S'
+    else
+        # Linux (GNU date) - use -d flag for date arithmetic
+        date -d '+1 hour' '+%H:%M:%S'
+    fi
+}
+
+# Get current timestamp in a basic format (fallback)
+# Returns: YYYY-MM-DD HH:MM:SS format
+get_basic_timestamp() {
+    date '+%Y-%m-%d %H:%M:%S'
+}
diff --git a/lib/response_analyzer.sh b/lib/response_analyzer.sh
index 30f8f03..df729e0 100644
--- a/lib/response_analyzer.sh
+++ b/lib/response_analyzer.sh
@@ -2,6 +2,9 @@
 # Response Analyzer Component for Ralph
 # Analyzes Claude Code output to detect completion signals, test-only loops, and progress
 
+# Source date utilities for cross-platform compatibility
+source "$(dirname "${BASH_SOURCE[0]}")/date_utils.sh"
+
 # Response Analysis Functions
 # Based on expert recommendations from Martin Fowler, Michael Nygard, Sam Newman
 
@@ -152,7 +155,7 @@ analyze_response() {
     cat > "$analysis_result_file" << EOF
 {
     "loop_number": $loop_number,
-    "timestamp": "$(date -Iseconds)",
+    "timestamp": "$(get_iso_timestamp)",
     "output_file": "$output_file",
     "analysis": {
         "has_completion_signal": $has_completion_signal,
diff --git a/ralph_loop.sh b/ralph_loop.sh
index 6881366..7cb03c4 100755
--- a/ralph_loop.sh
+++ b/ralph_loop.sh
@@ -7,6 +7,7 @@ set -e  # Exit on any error
 
 # Source library components
 SCRIPT_DIR="$(dirname "${BASH_SOURCE[0]}")"
+source "$SCRIPT_DIR/lib/date_utils.sh"
 source "$SCRIPT_DIR/lib/response_analyzer.sh"
 source "$SCRIPT_DIR/lib/circuit_breaker.sh"
 
@@ -164,14 +165,14 @@ update_status() {
     
     cat > "$STATUS_FILE" << STATUSEOF
 {
-    "timestamp": "$(date -Iseconds)",
+    "timestamp": "$(get_iso_timestamp)",
     "loop_count": $loop_count,
     "calls_made_this_hour": $calls_made,
     "max_calls_per_hour": $MAX_CALLS_PER_HOUR,
     "last_action": "$last_action",
     "status": "$status",
     "exit_reason": "$exit_reason",
-    "next_reset": "$(date -d '+1 hour' -Iseconds | cut -d'T' -f2 | cut -d'+' -f1)"
+    "next_reset": "$(get_next_hour_time)"
 }
 STATUSEOF
 }