That last e-mail encoding looks borked on my mailing list reader (the terminal), so I am sending the PKGBUILD again.
# Maintainer: Jamil SN
pkgname='datediff.sh'
pkgbase='shellDatediff'
pkgver=0.23.4
pkgrel=1
#epoch=
pkgdesc='Calculate time differences with Ksh, Bash, and Zsh builtins. Check moon phases, Easter dates and next Friday 13th.'
url='https://github.com/mountaineerbr/shellDatediff'
arch=('any')
license=('GPL')
depends=('bash')
optdepends=(
'date: convert input to iso-8601'
'bc: fractional time units (bash)'
)
provides=('datediff.sh')
#conflicts=('datediff.sh')
source=("https://github.com/mountaineerbr/${pkgbase}/releases/download/v${pkgver}/${pkgbase}.tar.zst")
md5sums=('949f88594bba40f7a62ff65e6dda7cf8')
prepare() {
cd "${pkgbase}-${pkgver}"
#check defaults interpreter
if command -v ksh
then return 0
elif command -v bash
then _sh=bash
elif command -v zsh
then _sh=zsh
else return 0
fi
sed -i -e "1s/ksh/${_sh}/" "${pkgname}"
}
package() {
cd "${pkgbase}-${pkgver}"
#install -Dm644 "${pkgname}.1" "${pkgdir}/usr/local/man/man1/${pkgname}.1"
install -Dm755 "${pkgname}" "${pkgdir}/usr/bin/${pkgname}"
}