Good Afternoon! You can get the details through the EPFO Portal. Just download the "EMPLOYER E-SEWA FORM No. 23" for the year the employee has resigned, and you will get the exact date of joining. You may also find the details on their payslip if you have in-house software where the date is maintained.
Other Ways to Maintain Employee Details
1. Create an Employee datasheet (Excel file) containing Employee Name, Address, DOB, DOJ, Gender, Salary Account Number, PF account Number, ESIC account number, etc.
2. You may also create a personal file that includes the resume, offer letter, joining documents like Photo ID proof, Address proof, Pan Card Xerox, Copy of Form - 2 (PF), Copy of Declaration Form (ESIC), Appointment, confirmation & Increment Letter Xerox, Agreement copy, Resignation Letter, or any other relevant documents.
I hope this information will help you as a fresher HR-Executive. All the best.