Eee no we don't?What you said was nothing more but period of time the warden could disappear that counts in years ,so we don't even know year of their disappearance.The warden pretty much could disappear anywhere from 9:37 to 9:40.
Yes, what I said was that the Warden disappeared between 9:37 and 9:40, which is the only thing we know for certain. There is absolutely no way we can pin down the precise date any further than that span of time. If I'd have to hazard a guess though, the Warden stopped communications at least a year before Inquisition, if Leliana has been without word from them for enough time to become concerned.
Hardly, easier when they pretty much outright break character for some players by things i mentioned before and that whole cure search that doesn't even make sense for good portion of wardens.
Yes, because even having not so much a "cure" as much as a potential way to remove the lethality of the Joining, while keeping the powers gained, isn't something that any Wardens would want to have? No Warden wants to miss out on dying in the Deep Roads instead of their beds, surrounded by children they find it hard to concieve with the darkspawn taint in their system?
Even if it's a pipe dream, the idea of a cure is a holy grail for the Wardens. Avernus spent over 200 years attempting to study the taint in order to find some breakthrough that could lead to such a discovery, so the HOF clearly isn't the first (and might not be the last) to go looking for it.
Inquisition takes place in 9:40 Dragon and ends in 9:41 Dragon. Leliana and Cassandra don't begin to search for the Warden until Divine Justinia calls for the Conclave and orders the construction of another Inquisition. It is then that they find that he/she and the Wardens of Ferelden have gone missing. This takes place at the very end of DA2 which takes place not too long before the beginning of DA:I, sometime between 9:39 and 9:40 Dragon.
Inquisition starts in 9:41 and supposedly ends by 9:42 (but I'd guess 9:43, at the very latest).
We know it must start later than 9:40 as the the Nevarran Accord has been broken and the Mage-Templar war has clearly been going on for some time, hence the reason for Justinia to begin sanctioning the formation of the new Inquistion.
Assuming that Cassandra wasn't in error when she gave the two year date since the death of Lambert at the end of Asunder, then one could reconcile that if we assume that she's being figurative, that it's nearly been two years. Since we know that Inquisition starts in late 9:41, that would make sense if Asunder was set in early 9:40.
Inquisition being set in late 9:41 can be seen by the fact that winter is approaching, as numerous people in the Hinterlands mention that it's getting colder and many fear the refugees there will starve or freeze to death soon. Similarly, the Dark Future is explicitly stated to be in Harvestmere (the tenth month in the calendar) of 9:42, reinforcing the idea we skipped over an entire year.
The end of Inquisition is a little hard to pin down. While Corypheus had gained the army of demons and had Celene assassinated by Harvestmere 9:42 in the Dark Future, at the same time, the Inquisitor was not around to help thwart any of his plans. Our interference might have been the factor that ended up delaying some of Corypheus' plans in the non-Dark Future (regardless of whether we chose the Templar and Mage path) as we were able to successfully steal more than one army away from him that he used in the Dark Future, forcing him to retreat and regroup.
While travel times across Thedas are annoying vague, it can't be large enough that it'd add years onto the journey times, as save for natural obstacles such as Lake Calenhad or the Frostbacks, we're dealing with mostly main roads across Ferelden and Orlais to travel along. Orlais is only a problem as the Civil War has disrupted traffic (as we saw in the novels), but that'd only delay people slightly out of the way by a few days or weeks at the most.