You can think of difficulty in terms of forward (more than) time or backward (less than) time. They are equivalent amounts of time, but may feel different psychologically. It's probably good to keep both in mind.
Level |
Description |
More than... |
Less than... |
D1 |
Trivial |
a few minutes |
an hour |
D2 |
Easy |
an hour |
half a day |
D3 |
Simple |
a few hours |
a day |
D4 |
Hard |
a day |
half a week |
D5 |
Vague |
Potentially a week |
or more |
Level |
Hours |
Days |
D1 |
1.0 |
0.2 |
D2 |
2.5 |
0.5 |
D3 |
5.0 |
1.0 |
D4 |
15. |
3.0 |
D5 |
-.- |
-.- |
D5
is Incalculable and must be flagged, better defined, or broken down further.
Months |
Weeks |
Days |
Hours |
1.0 |
4.0 |
20.0 |
100.0 |
0.25 |
1.0 |
5.0 |
25.0 |
0.05 |
0.20 |
1.0 |
5.0 |
0.01 |
0.04 |
0.2 |
1.0 |
- 1 day = 5 hours
- 1 week = 5 days
- 1 month = 20 days