How long has Ianto been working at TW3 when Gwen starts there?
How long after that before the Cyberwoman episode happens?
And roughly how long is it after Lisa dies, before the events in TKKS?
I mean, are we talking weeks... months...? Couldn't be years, as he's only been there for 21 months by the end of series two, but as far as I'm aware, that's the only occasion a definite indication of time is given.
Any help greatly appreciated!