- At company X, I was offered a job at "The new office", A, which "We will be opening soon".
- The manager of the "new office" resigned, office A did not materialize.
- While a replacement for the manager was sought, my contract got placed with office B, while I started work at office C, which is across a nearby country border.
- Six months ago, everyone agreed that I would stay at C for now, and so my contract was transferred there.
At the time, I was only vaguely aware that salaries were higher across the border. Now my current boss, at C, has without previous inquiry from me on the subject sent me an e-mail saying, in short
You are entitled to a higher salary, in 6 months you'll get a 20% raise.
My question is, if I should have a higher salary, is there a reason I should wait 6 months to get it? Is there a reason I should not have it retro-actively? Am I just being greedy?
I read the FAQ, but I'm still uncertain as to whether this is on-topic or not. After reading this meta question are-questions-about-careers-off-topic, I decided to post.