From b4519697dd90b952b2371180e23842762b66dd40 Mon Sep 17 00:00:00 2001
From: Caleb Stanford <caleb.pirsquared@gmail.com>
Date: Tue, 19 Jul 2022 19:05:35 -0400
Subject: [PATCH] rm dependence on chrono, replace with time 0.3.11
 (https://github.com/chronotope/chrono/issues/499)

---
 Cargo.lock  | 55 ++++++++++-------------------------------------------
 Cargo.toml  |  2 +-
 src/util.rs | 12 ++++++++++--
 3 files changed, 21 insertions(+), 48 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e871ab9..f1216ef 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -22,12 +22,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "autocfg"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
-
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -40,19 +34,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "chrono"
-version = "0.4.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
-dependencies = [
- "libc",
- "num-integer",
- "num-traits",
- "time",
- "winapi",
-]
-
 [[package]]
 name = "clap"
 version = "2.34.0"
@@ -82,7 +63,7 @@ checksum = "4eb1a864a501629691edf6c15a593b7a51eebaa1e8468e9ddc623de7c9b58ec6"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
@@ -122,22 +103,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
 [[package]]
-name = "num-integer"
-version = "0.1.45"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
-dependencies = [
- "autocfg",
- "num-traits",
-]
-
-[[package]]
-name = "num-traits"
-version = "0.2.15"
+name = "num_threads"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
+checksum = "2819ce041d2ee131036f4fc9d6ae7ae125a3a40e97ba64d04fe799ad9dabbb44"
 dependencies = [
- "autocfg",
+ "libc",
 ]
 
 [[package]]
@@ -259,12 +230,12 @@ dependencies = [
 name = "state_graph"
 version = "0.1.0"
 dependencies = [
- "chrono",
  "disjoint-sets",
  "rand",
  "serde",
  "serde_json",
  "structopt",
+ "time",
 ]
 
 [[package]]
@@ -319,13 +290,13 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.1.44"
+version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6db9e6914ab8b1ae1c260a4ae7a49b6c5611b40328a735b21862567685e73255"
+checksum = "72c91f41dcb2f096c05f0873d667dceec1087ce5bcf984ec8ffb19acddbb3217"
 dependencies = [
+ "itoa",
  "libc",
- "wasi 0.10.0+wasi-snapshot-preview1",
- "winapi",
+ "num_threads",
 ]
 
 [[package]]
@@ -358,12 +329,6 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
-[[package]]
-name = "wasi"
-version = "0.10.0+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a143597ca7c7793eff794def352d41792a93c481eb1042423ff7ff72ba2c31f"
-
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
diff --git a/Cargo.toml b/Cargo.toml
index 1b369cc..d6014e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,12 +7,12 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-chrono = "0.4.15"
 disjoint-sets = "0.4.2"
 rand = "0.8.5"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 structopt = "0.3.21"
+time = { version = "0.3.11", features = ["formatting"] }
 
 [lib]
 doctest = false
diff --git a/src/util.rs b/src/util.rs
index 3c558f4..1a47071 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -4,7 +4,6 @@
     (File I/O, JSON serialization, system time, etc.)
 */
 
-use chrono::offset::Local;
 use serde::de::DeserializeOwned;
 use serde::ser::Serialize;
 use std::fmt::Debug;
@@ -12,6 +11,7 @@ use std::fs::{self, File};
 use std::io::{self, BufReader, BufWriter, Write};
 use std::path::{Path, PathBuf};
 use std::time::{Duration, SystemTime};
+use time::{format_description, OffsetDateTime};
 
 /*
     File I/O
@@ -134,8 +134,16 @@ pub fn time_since(t: &SystemTime) -> Duration {
 }
 
 // Current datetime for use in file names
+// Note: removed dependence on chrono on 2022-07-19; as a result,
+// now this uses time::OffsetDateTime, which is UTC rather than local time.
 pub fn current_datetime_str() -> String {
-    Local::now().format("%Y-%m-%d-%H%M%S").to_string()
+    let dt: OffsetDateTime = SystemTime::now().into();
+    let dt_fmt = format_description::parse(
+        "[year]-[month]-[day]-[hour][minute][second]"
+    ).unwrap();
+    dt.format(&dt_fmt).unwrap()
+    // Old implementation using Chrono
+    // Local::now().format("%Y-%m-%d-%H%M%S").to_string()
 }
 
 #[test]