describe() for Dates

[jtrakk]

describe() doesn't give much information about Dates.

DataFrames.describe(Dates.Date.(2000:2005))
Summary Stats:
Length:         6
Type:           Dates.Date
Number Unique:  6

whereas describe(1:4) gives more info.

Summary Stats:
Length:         4
Missing Count:  0
Mean:           2.500000
Minimum:        1.000000
1st Quartile:   1.750000
Median:         2.500000
3rd Quartile:   3.250000
Maximum:        4.000000
Type:           Int64

[nalimilan]

Currently we only compute these informations for numbers. What we could do instead is try to compute them, and if that fails fall back to the output for categorical data.

[jtrakk]

When the dates are embedded in a DataFrame, describe() does give min/max:

describe(DataFrame(a=Date.(2000:2005)))
1×8 DataFrame
│ Row │ variable │ mean    │ min        │ median  │ max        │ nunique │ nmissing │ eltype   │
│     │ Symbol   │ Nothing │ Date       │ Nothing │ Date       │ Int64   │ Nothing  │ DataType │
├─────┼──────────┼─────────┼────────────┼─────────┼────────────┼─────────┼──────────┼──────────┤
│ 1   │ a        │         │ 2000-01-01 │         │ 2005-01-01 │ 6       │          │ Date     │

but it's missing the other quantiles.