diff --git a/packages/dates_calc/dates_calc.0.0.7/opam b/packages/dates_calc/dates_calc.0.0.7/opam
new file mode 100644
index 00000000000..05edc0b49b1
--- /dev/null
+++ b/packages/dates_calc/dates_calc.0.0.7/opam
@@ -0,0 +1,43 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "A date calculation library"
+description: """
+A date calculation library, with exact operators to add a given
+ number of days to a date, and approximate operators to add months or
+ years."""
+maintainer: ["Raphaël Monat <raphael.monat@lip6.fr>"]
+authors: ["Aymeric Fromherz" "Denis Merigoux" "Raphaël Monat" "Louis Gesbert"]
+license: "Apache-2.0"
+homepage: "https://github.com/CatalaLang/dates-calc"
+bug-reports: "https://github.com/CatalaLang/dates-calc/issues"
+depends: [
+  "dune" {>= "3.11"}
+  "ocaml" {>= "4.11.0"}
+  "alcotest" {with-test & >= "1.5.0"}
+  "qcheck" {with-test & >= "0.15"}
+  "conf-python-3" {with-test}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/CatalaLang/dates-calc.git"
+url {
+  src:
+    "https://github.com/CatalaLang/dates-calc/archive/refs/tags/0.0.7.tar.gz"
+  checksum: [
+    "md5=244294deee9c01082ee847d66ff1ef48"
+    "sha512=1756ed2d87f0d4d67e850de8445136d08dbcd959779f189dacbe880afdbc4c6a9ecca843f94df48181302b31ceb7faeef307179473648efbf4ffdc8d5223ec66"
+  ]
+}