+} # Report seconds until next day
+timeUntilNextHour(){
+    # Desc: Report seconds until next hour
+    # Output: stdout: integer seconds until next hour
+    # Output: exit code 0 if stdout > 0; 1 if stdout = 0; 2 if stdout < 0
+    # Usage: timeUntilNextHour
+    # Usage: if ! myTTL="$(timeUntilNextHour)"; then yell "ERROR in if statement"; exit 1; fi
+    local returnState TIME_CURRENT TIME_NEXT_HOUR SECONDS_UNTIL_NEXT_HOUR
+    TIME_CURRENT="$(date --iso-8601=seconds)"; # Produce `date`-parsable current timestamp with resolution of 1 second.
+    TIME_NEXT_HOUR="$(date -d "$TIME_CURRENT next hour" --iso-8601=hours)"; # Produce `date`-parsable current time stamp with resolution of 1 second.
+    SECONDS_UNTIL_NEXT_HOUR="$(( $(date +%s -d "$TIME_NEXT_HOUR") - $(date +%s -d "$TIME_CURRENT") ))"; # Calculate seconds until next hour (res. 1 second).
+    if [[ "$SECONDS_UNTIL_NEXT_HOUR" -gt 0 ]]; then
+       returnState="true";
+    elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -eq 0 ]]; then
+       returnState="WARNING_ZERO";
+       yell "WARNING:Reported time until next hour exactly zero.";
+    elif [[ "$SECONDS_UNTIL_NEXT_HOUR" -lt 0 ]]; then
+       returnState="WARNING_NEGATIVE";
+       yell "WARNING:Reported time until next hour is negative.";
+    fi
+
+    try echo "$SECONDS_UNTIL_NEXT_HOUR"; # Report
+    
+    #===Determine function return code===
+    if [[ "$returnState" = "true" ]]; then
+       return 0;
+    elif [[ "$returnState" = "WARNING_ZERO" ]]; then
+       return 1;
+    elif [[ "$returnState" = "WARNING_NEGATIVE" ]]; then
+       return 2;
+    fi
+} # Report seconds until next hour