diff --git a/src/graphics/Screen.cpp b/src/graphics/Screen.cpp
index 09cafc348..c5b428537 100644
--- a/src/graphics/Screen.cpp
+++ b/src/graphics/Screen.cpp
@@ -70,6 +70,8 @@ static char btPIN[16] = "888888";
 
 uint32_t logo_timeout = 5000; // 4 seconds for EACH logo
 
+uint32_t hours_in_month = 730;
+
 // This image definition is here instead of images.h because it's modified dynamically by the drawBattery function
 uint8_t imgBattery[16] = {0xFF, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0xE7, 0x3C};
 
@@ -386,10 +388,11 @@ static void drawTextMessageFrame(OLEDDisplay *display, OLEDDisplayUiState *state
     uint32_t days = hours / 24;
 
     if (config.display.heading_bold) {
-        display->drawStringf(1 + x, 0 + y, tempBuf, "%s ago from %s", screen->drawTimeDelta(days, hours, minutes, seconds),
+        display->drawStringf(1 + x, 0 + y, tempBuf, "%s ago from %s",
+                             screen->drawTimeDelta(days, hours, minutes, seconds).c_str(),
                              (node && node->has_user) ? node->user.short_name : "???");
     }
-    display->drawStringf(0 + x, 0 + y, tempBuf, "%s ago from %s", screen->drawTimeDelta(days, hours, minutes, seconds),
+    display->drawStringf(0 + x, 0 + y, tempBuf, "%s ago from %s", screen->drawTimeDelta(days, hours, minutes, seconds).c_str(),
                          (node && node->has_user) ? node->user.short_name : "???");
 
     display->setColor(WHITE);
@@ -794,9 +797,6 @@ static void drawNodeInfo(OLEDDisplay *display, OLEDDisplayUiState *state, int16_
     else if (agoSecs < 120 * 60) // last 2 hrs
         snprintf(lastStr, sizeof(lastStr), "%u minutes ago", agoSecs / 60);
     else {
-
-        uint32_t hours_in_month = 730;
-
         // Only show hours ago if it's been less than 6 months. Otherwise, we may have bad
         //   data.
         if ((agoSecs / 60 / 60) < (hours_in_month * 6)) {
@@ -1336,17 +1336,20 @@ void Screen::blink()
     dispdev.setBrightness(brightness);
 }
 
-String Screen::drawTimeDelta(uint32_t days, uint32_t hours, uint32_t minutes, uint32_t seconds)
+std::string Screen::drawTimeDelta(uint32_t days, uint32_t hours, uint32_t minutes, uint32_t seconds)
 {
-    String uptime;
-    if (days >= 2)
-        uptime = String(days) + "d";
+    std::string uptime;
+
+    if (days > (hours_in_month * 6))
+        uptime = "?";
+    else if (days >= 2)
+        uptime = std::to_string(days) + "d";
     else if (hours >= 2)
-        uptime = String(hours) + "h";
+        uptime = std::to_string(hours) + "h";
     else if (minutes >= 1)
-        uptime = String(minutes) + "m";
+        uptime = std::to_string(minutes) + "m";
     else
-        uptime = String(seconds) + "s";
+        uptime = std::to_string(seconds) + "s";
     return uptime;
 }
 
@@ -1714,7 +1717,7 @@ void DebugInfo::drawFrameSettings(OLEDDisplay *display, OLEDDisplayUiState *stat
     display->setColor(WHITE);
 
     // Show uptime as days, hours, minutes OR seconds
-    String uptime = screen->drawTimeDelta(days, hours, minutes, seconds);
+    std::string uptime = screen->drawTimeDelta(days, hours, minutes, seconds);
 
     uint32_t rtc_sec = getValidTime(RTCQuality::RTCQualityDevice);
     if (rtc_sec > 0) {
@@ -1729,12 +1732,12 @@ void DebugInfo::drawFrameSettings(OLEDDisplay *display, OLEDDisplayUiState *stat
         int min = (hms % SEC_PER_HOUR) / SEC_PER_MIN;
         int sec = (hms % SEC_PER_HOUR) % SEC_PER_MIN; // or hms % SEC_PER_MIN
 
-        char timebuf[9];
+        char timebuf[10];
         snprintf(timebuf, sizeof(timebuf), " %02d:%02d:%02d", hour, min, sec);
         uptime += timebuf;
     }
 
-    display->drawString(x, y + FONT_HEIGHT_SMALL * 1, uptime);
+    display->drawString(x, y + FONT_HEIGHT_SMALL * 1, uptime.c_str());
 
     // Display Channel Utilization
     char chUtil[13];
diff --git a/src/graphics/Screen.h b/src/graphics/Screen.h
index 1d732ad4c..5e92e73bb 100644
--- a/src/graphics/Screen.h
+++ b/src/graphics/Screen.h
@@ -207,7 +207,7 @@ class Screen : public concurrency::OSThread
     }
 
     /// generates a very brief time delta display
-    String drawTimeDelta(uint32_t days, uint32_t hours, uint32_t minutes, uint32_t seconds);
+    std::string drawTimeDelta(uint32_t days, uint32_t hours, uint32_t minutes, uint32_t seconds);
 
     /// Overrides the default utf8 character conversion, to replace empty space with question marks
     static char customFontTableLookup(const uint8_t ch)