Estimate
From APIDesign
Estimating future is hard. As a result Oracle requires its employees to never commit to particular release dates publicly. We can talk about the dates, but we have to mention they are just estimates. There is a special, law oriented language expressing this which is supposed to be included in every presentation that mentions future Oracle product plans.
Using Wide Range
I found the language weird, but I understand the purpose. To comply with the goal while avoiding the weirdness I am using a range that includes past. For example, now in March, 2013 I would say:
NetBeans 7.3.1 is going to be released in May 2013 - plus/minus six months.
I am hoping the fact that the beginning of the interval already happened and the 7.3.1 version has not been released yet will hint everyone to treat the above statement as a rough estimate only.
Seems to Work
The wide range estimate seems to work. Today I received following analysis:
Additionally, I see that your planning is more or less like our, but you can also deliver in the past!! If the delivery is in May 2013 plus or minus six months, it could be that you are going to deliver last Xmas (2012) :-)
This is cool!
Thanks, that is why I am using the wide range! Time to explain the history behind this kind of estimates...
Plus/Minus 200 Years
The idea is based on famous (among Czechs) play of theater of Jára Cimrman. In the play a group of historians is trying to find a date when Cimrman arrived into village Liptákov.
One of them decides to calculate the time by measuring radioactive decay of carbon found on Cimrman boots and concludes that Cimrman arrived in 1905 plus/minus two hundred years. Another one abase to old fashioned method of reading the village chronicle to find out it dates Cimrman's arrival to September 1905.
Should not we call this kind of estimate - Cimrman's estimate? Planning based on this estimate could be called Cimrman's planning!