Switch case (millis()) UPDATED I want to create a sketch that counts the days from the moment the &quot;project&quot; start and send and osc message every two days (or more) for 3 weeks. So:

day zero : osc message -> 0
day two. : osc message -> 1
day four : osc message -> 2

etc.
I'm trying to create a state machine to send the messages when the millis reaches a certain time it should print message and so on for the other times.
I'm giving a small example:
I went with @jsotola's suggestion and tried out the BlinkWithoutDelay approach. It seemingly works because I get serial prints around the correct millis() they are printed in 4fold or 3fold the messages.
EDITED CODE:
int daytwo = 25920; // for testing purposes other numbers then the actual millis()
int dayfour = 44400;
    
void loop() {  
  unsigned long currentMillis = millis();   // store current time

  if (currentMillis == daytwo) {
    Serial.println(&quot;daytwo&quot;);
  }
    
  if (currentMillis == dayfour) {
    Serial.println(&quot;dayfour&quot;);
  }
}

Serial output:

    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.889 -> daytwo
    11:04:39.926 -> daytwo
    11:04:58.366 -> dayfour
    11:04:58.366 -> dayfour
    11:04:58.366 -> dayfour
    11:04:58.366 -> dayfour
The following code is not very &quot;clean&quot; but easy to understand. Use a variable to hold the day, you have already printed and check in which interval you are. If you change the 2 day interval print a message and set the actDay variable to the number of the day you have already printed; to avoid repprinting it again.
int daytwo = 25920; 
int dayfour = 44400;

int actDay = -1;

void loop() 
{  
  unsigned long currentMillis = millis();
  if (currentMillis &lt; daytwo) 
  {
    if ( actDay != 0 ) 
    {
      actDay = 0;
      Serial.println(&quot;dayzero&quot;);
    }
  }
  else if (currentMillis &lt; dayfour ) 
  {
    if ( actDay != 2 ) 
    {
      actDay = 2;
      Serial.println(&quot;daytwo&quot;);
    }
  }
  else 
  {
    if ( actDay != 4 ) 
    {
      actDay = 4;
      Serial.println(&quot;dayfour&quot;);
    }
  } 
}