How do I get the date a Mamba environment was created?

I'd like to see the date I made a mamba environment on my linux machine. I can't find anything in the docs for this. I tried the following command, but it didn't give me the info I wanted: mamba env export --from-history -n moose_peacock

Any suggestions (other than detective work with package version release dates)?

Conda Metadata

Conda environments¹ keep metadata in the ${CONDA_PREFIX}/conda-meta folder and specifically the first line of the ${CONDA_PREFIX}/conda-meta/history file records the date of the first transaction (creation).

Example: Single Environment

Let's create an environment and then check the first few lines of the history file:

Interactive (Activating) Environment

$ mamba create -n foo
$ mamba activate foo
(foo) $ head -n3 ${CONDA_PREFIX}/conda-meta/history
==> 2023-11-06 23:59:57 <==
# cmd: /Users/user/miniconda3/bin/mamba create -n foo
# conda version: 23.7.4

Single-Line Command with Conda Run

$ mamba run -n foo bash -c "head -n3 \${CONDA_PREFIX}/conda-meta/history"
==> 2023-11-06 23:59:57 <==
# cmd: /Users/user/miniconda3/bin/mamba create -n foo
# conda version: 23.7.4

Script for All Environments

The following bash script will list this information for all non-base environments:

show-env-creation-all.sh

#!/bin/bash -l                                                                                                                        

_CONDA_PREFIX=$(conda run -n base bash -c "echo \${CONDA_PREFIX}")

for env in ${_CONDA_PREFIX}/envs/*; do
    if [ -d "$env" ]; then
        echo "Environment: $(basename $env)"
        head -n3 "$env/conda-meta/history"
        echo " "
    fi
done

which can be run with:

bash -l show-env-creation-all.sh

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_{[1]: The term "Mamba environment" is a misnomer. Mamba is an interface for Conda environments - it's all still Conda.}