Try this:
#include <TimeLib.h>
void TimeShowFormatted(int ms) {
long days = 0;
long hours = 0;
long mins = 0;
long secs = 0;
String secs_o = ":";
String mins_o = ":";
String hours_o = ":";
secs = ms / 1000; // set the seconds remaining
mins = secs / 60; //convert seconds to minutes
hours = mins / 60; //convert minutes to hours
days = hours / 24; //convert hours to days
secs = secs - (mins * 60); //subtract the coverted seconds to minutes in order to display 59 secs max
mins = mins - (hours * 60); //subtract the coverted minutes to hours in order to display 59 minutes max
hours = hours - (days * 24); //subtract the coverted hours to days in order to display 23 hours max
if (secs < 10) {
secs_o = ":0";
}
if (mins < 10) {
mins_o = ":0";
}
if (hours < 10) {
hours_o = ":0";
}
return days + hours_o + hours + mins_o + mins + secs_o + secs;
}
Usage is:
Blynk.virtualWrite(V4, TimeShowFormatted(millis()));