Which libraries for DS1302 real time clock and WS2811 LED strip do not conflict?
I installed a library from within the IDE as StarCat suggested.

https://github.com/Makuna/Rtc

#include &lt;FastLED.h&gt;
#include &lt;ThreeWire.h&gt; 
#include &lt;RtcDS1302.h&gt;

#define NUM_LEDS 50
#define DATA_PIN 6

ThreeWire myWire(3,4,2); // IO, SCLK, CE
RtcDS1302&lt;ThreeWire&gt; Rtc(myWire);

CRGB leds[NUM_LEDS];

void setup() { 
   FastLED.addLeds&lt;WS2811, DATA_PIN, RGB&gt;(leds, NUM_LEDS);
   Rtc.Begin();
}

void loop() {
   RtcDateTime dt = Rtc.GetDateTime();

   for (int i=0; i&lt;NUM_LEDS;i++) {
     leds[i] = CRGB::Red;
   }

FastLED.show();
delay(100);
}


I am able to get and use the time, and the LED output works.