Hi to all respondents to my query. Many thanks for inputs.That I am so new to this field that millis() reverts to zero after 4294967295 milliseconds was information to me. My sketch envisages giving manually IntialHour,InitialMintue to start the loop part of the sketch,since Seconds and milliseconds would not be accurate manually! I could do so by connecting to PC,downloading current time of PC and start clock at that time. However, it is presently beyond my skill!
But can I have something similar to below to continue the lock after rollover crisis?
Loop
if (millis() !=0)
{regular working part of the program;}
else {InitialHour=PresentHour;InitalMinute=PresentMinute;InitialSecond=PresentSecond ;InitialMilli=PresentMilli;
regular working part of the program;}
sureshparanjape