My oh-my-zsh theme, a derivative of the Soliah theme

zanshin.zsh-theme

# Shows little symbol '±' if you're currently at a git repo and '○' all other times
function prompt_char {
    git branch >/dev/null 2>/dev/null && echo '±' && return
    echo '○'
}

PROMPT='
%{$fg[blue]%}%n%{$reset_color%} on %{$fg[yellow]%}%m%{$reset_color%} in %{$fg[green]%}%~%b%{$reset_color%} $(git_time_since_commit)$(check_git_prompt_info)
${vcs_info_msg_0_}$(prompt_char) '

# rubies are red, and my rprompt is too
RPROMPT='%{$fg[tan]%}$(rvm_ruby_prompt)%{$reset_color%}%'


ZSH_THEME_GIT_PROMPT_PREFIX="%{$fg[white]%}"
ZSH_THEME_GIT_PROMPT_SUFFIX="%{$reset_color%})"

# Text to display if the branch is dirty
ZSH_THEME_GIT_PROMPT_DIRTY="%{$fg[red]%} *%{$reset_color%}" 

# Text to display if the branch is clean
ZSH_THEME_GIT_PROMPT_CLEAN="" 

# Colors vary depending on time lapsed.
ZSH_THEME_GIT_TIME_SINCE_COMMIT_SHORT="%{$fg[green]%}"
ZSH_THEME_GIT_TIME_SHORT_COMMIT_MEDIUM="%{$fg[yellow]%}"
ZSH_THEME_GIT_TIME_SINCE_COMMIT_LONG="%{$fg[red]%}"
ZSH_THEME_GIT_TIME_SINCE_COMMIT_NEUTRAL="%{$fg[cyan]%}"

# display Ruby information, only when RVM is installed and only when you are using a RVM installed ruby.
function rvm_ruby_prompt {
    ruby_version=$(~/.rvm/bin/rvm-prompt)
    if [ -n "$ruby_version" ]; then
		echo "[$ruby_version]"
	fi
}

# Git sometimes goes into a detached head state. git_prompt_info doesn't
# return anything in this case. So wrap it in another function and check
# for an empty string.
function check_git_prompt_info() {
    if git rev-parse --git-dir > /dev/null 2>&1; then
        if [[ -z $(git_prompt_info) ]]; then
            echo "%{$fg[magenta]%}detached-head%{$reset_color%})"
        else
            echo "$(git_prompt_info)"
        fi
    fi
}

# Determine if we are using a gemset.
function rvm_gemset() {
    GEMSET=`rvm gemset list | grep '=>' | cut -b4-`
    if [[ -n $GEMSET ]]; then
        echo "%{$fg[yellow]%}$GEMSET%{$reset_color%}|"
    fi 

}

# Determine the time since last commit. If branch is clean,
# use a neutral color, otherwise colors will vary according to time.
function git_time_since_commit() {
    if git rev-parse --git-dir > /dev/null 2>&1; then
        # Only proceed if there is actually a commit.
        if [[ $(git log 2>&1 > /dev/null | grep -c "^fatal: bad default revision") == 0 ]]; then
            # Get the last commit.
            last_commit=`git log --pretty=format:'%at' -1 2> /dev/null`
            now=`date +%s`
            seconds_since_last_commit=$((now-last_commit))

            # Totals
            MINUTES=$((seconds_since_last_commit / 60))
            HOURS=$((seconds_since_last_commit/3600))
           
            # Sub-hours and sub-minutes
            DAYS=$((seconds_since_last_commit / 86400))
            SUB_HOURS=$((HOURS % 24))
            SUB_MINUTES=$((MINUTES % 60))
            
            if [[ -n $(git status -s 2> /dev/null) ]]; then
                if [ "$MINUTES" -gt 30 ]; then
                    COLOR="$ZSH_THEME_GIT_TIME_SINCE_COMMIT_LONG"
                elif [ "$MINUTES" -gt 10 ]; then
                    COLOR="$ZSH_THEME_GIT_TIME_SHORT_COMMIT_MEDIUM"
                else
                    COLOR="$ZSH_THEME_GIT_TIME_SINCE_COMMIT_SHORT"
                fi
            else
                COLOR="$ZSH_THEME_GIT_TIME_SINCE_COMMIT_NEUTRAL"
            fi

            if [ "$HOURS" -gt 24 ]; then
                echo "($(rvm_gemset)$COLOR${DAYS}d${SUB_HOURS}h${SUB_MINUTES}m%{$reset_color%}|"
            elif [ "$MINUTES" -gt 60 ]; then
                echo "($(rvm_gemset)$COLOR${HOURS}h${SUB_MINUTES}m%{$reset_color%}|"
            else
                echo "($(rvm_gemset)$COLOR${MINUTES}m%{$reset_color%}|"
            fi
        else
            COLOR="$ZSH_THEME_GIT_TIME_SINCE_COMMIT_NEUTRAL"
            echo "($(rvm_gemset)$COLOR~|"
        fi
    fi
}