Seniority date is normally defined as the date from which seniority is calculated.
Anniversary date is normally defined as the date from which anniversary is calculated.
The date stated in both Seniority date and Anniversary date is normally the same as in Original hire date which is the date when the employee was hired in.
But the dates for
* Seniority
* Anniversary
* Original hire
might differ due to certain circumstances and policies within the company.
Examples with different dates:
1.
Adam has been working at company A since 05.01.2015.
Company A is sold to to company B on 10.01.2018..
Company B is hiring Adam on 10.01.2018.
* Original hire date for Adam = 10.01.2018 (Effective date of the sale of company A and hire date for Adam)
* Seniority date for Adam = 05.01.2015 (Hire date for Adam in Company A)
* Anniversary date for Adam = 05.01.2015 (same as Seniority date)
2.
Brian has been working at company A since 07.01.2012.
Brian was hourly paid during his first years since he was working as a student worker until 08.01.2014.
Company A is sold to company B. Brian is hired in company B on 10.01.2018.
* Original hire date for Brian = 10.01.2018 (Effective date of the sale of company A and hire date for Brian)
* Seniority date for Brian = 07.01.2012 (Hire date for Brian in Company A)
* Anniversay date for Brian = 08.01.2014 (the date he started working full-time in Company A)