Rename multiple file types

[Preetish]

hello,

I have several file type 2003_050
With the year 2003 and the day 050 days of the year, making March 19.
I want to use a program to convert all my file number in dd / mm / yyyy.

Thank you for your reply

[Abraham.J]

Frankly, I rather recommend yyyy-mm-dd format (for correct sorting in Explorer).

But apart from that, no, I do not know of any program for that.

[Preetish]

Yes you're right but no matter what the format is essential to make the conversion.
Thanks for your suggestion.

[DllD]

For the conversion you can do like this:

conv.bat

 @ echo off 

  set example = 2003_050 

  :: Extraction of the Year 
  set A =% EXAMPLE: ~ 0.4% 

  :: Extraction of Quanti?me 
  set / a Q = 1% EXAMPLE: ~ 5,3% - 1000 

  :: Calculation of Julian day from 1 January of the year%% A +% Q% days 
  set / a = JJ% Q% + ((1461 * (% A +% 4800 + (1 - 14) / 12)) / 4 + (367 * (1 - 2 - 12 * ((1 - 14) / 12 ))) / 12 - (3 * ((%% A + 4900 + (1 - 14) / 12) / 100)) / 4 + 1 - 32075) - 1 

  :: Convert Julian Day to Day (% J%), Month (M%%) and Year (% A%) 
  set / a T0 =% DD% + 68569 
  set / a T1 = (T0 *% 4%) / 146097 
  set / a T0 = T0%% - (146097 *% Q1% + 3) / 4 
  set / a T2 = (4000 * (%% T0 + 1)) / 1461001 
  set / a T0 = T0%% - (1461 *% Q2%) / 4 + 31 
  set / a T3 = (80 *% T0%) / 2447 
  set / a J = T0%% - (2447 *% Q3%) / 80 
  set / a M =% Q3% + 2 - (12 * (% Q3% / 11)) 
  set / a A = 100 * (% Q1% - 49) +% +% Q2 (% T3% / 11) 

  :: Formatting resultat 
  if% J% LSS 10 set J = J% 0% 
  if% M% LSS 10 set M = M% 0% 

  echo. 
  Before conversion echo:%% EXAMPLE 
  echo after conversion:% A% M% _% _% J% 
  echo.  & Pause

Result

Before conversion: 2003_050
After conversion: 2003_02_19

Press any key to continue ...

[Preetish]

I thank you for your answer but I am not programming savvy therefore you can tell me how to run this program (with what software);
On the other hand is what the code you have given m I can directly rename a file or I have to do an extra manipulation?

Actually I managed to run the script by creating a bat file. But how I do I do if I want to rename the file name.

Thank you for your answer