Losing my whole Keychain has hit me hard. Thankfully, the SE community has been extremely helpful. Here's another one I need to find. This one is the passcode for my iPad. It's 6 digits.

No password hint on this one.

The process I used to get to the password (stored in my email, thankfully).

When I started to reach up high
I dreamt I'd reach the highest sky
Square a square and it would be
Yet the moon's days still elude me.

• The "highest sky" might refer to Seven Heavens, en.wikipedia.org/wiki/Seven_Heavens and "reach up high" might refer to "High five". Mar 18, 2016 at 17:36

Is it:

614656

When I started to reach up high
I dreamt I'd reach the highest sky

At 614656m you are in the exosphere (the outer layer of the atmosphere)

Square a square and it would be
Yet the moon's days still elude me.

The moon goes in cycles of 28 days and (28^2)^2 is 614656. Squaring a square of the "moon's days" or days in a moonth.

• I like the direction of your thinking here. Just a note that the moon's day/orbit cycle is just over 27 days rather than 30 which throws the exosphere numbers out. Mar 18, 2016 at 12:58
• I was going more along the "moonth" logic so let me adjust numbers. Also still in exosphere above 500km. Mar 18, 2016 at 14:25
• ~29.5 days, but lunar cycles, months, and moonths have never been quite in agreement. It's something between 28 and 30 which I believe would result in the answer you're looking for. Hence the reason I first chose 30 as 29.52... Rounds to 30 and an irrational number would not result in a 6 digit code. Mar 18, 2016 at 17:54
• The lenght of a lunar cycle might be 27.555 or 27.322 or 27.212 or 29.531, depending on whether you use the anomalistic, sidereal, tropical, draconic, or synodic version: en.wikipedia.org/wiki/Lunar_month . Mar 18, 2016 at 18:03
• Exactly, so without further hint, I don't believe it's solvable (without a total guess) unless there is something in those 4 lines that was completely missed. Mar 18, 2016 at 18:06