From c11aefb9635dc18ab87d00c59a669c4f223f3f1e Mon Sep 17 00:00:00 2001
From: lew <lew@ily.rs>
Date: Wed, 1 Apr 2026 22:39:11 +0100
Subject: [PATCH] fix: fail on explicitly past dates, rather than pushing
 forwards to always tomorrow

---
 nag           | 14 ++++++++++++--
 test/nag.bats |  5 +++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/nag b/nag
index c4c5755..1b9ee4c 100755
--- a/nag
+++ b/nag
@@ -556,8 +556,8 @@ _format_time() {
 #
 # Description:
 #   Parse a human-readable time string via `date -d` and print a unix
-#   timestamp. If the resulting time is in the past, roll forward to
-#   the same time-of-day tomorrow.
+#   timestamp. If the time is earlier today, roll forward to tomorrow.
+#   If the date is explicitly in the past (a previous day), error.
 _parse_time() {
   local _time_str="${1:-}"
   [[ -n "${_time_str}" ]] || _exit_1 printf "No time specified.\\n"
@@ -571,6 +571,16 @@ _parse_time() {
 
   if [[ "${_timestamp}" -le "${_now}" ]]
   then
+    local _parsed_date _today
+    _parsed_date="$(date -d "@${_timestamp}" +%Y-%m-%d)"
+    _today="$(date +%Y-%m-%d)"
+
+    if [[ "${_parsed_date}" != "${_today}" ]]
+    then
+      _exit_1 printf "Time is in the past: %s.\\n" "${_time_str}"
+    fi
+
+    # Today but already passed: roll to tomorrow same time.
     local _time_of_day
     _time_of_day="$(date -d "@${_timestamp}" +%H:%M:%S)"
     _timestamp="$(date -d "tomorrow ${_time_of_day}" +%s)" ||
diff --git a/test/nag.bats b/test/nag.bats
index 45ee66c..c22d172 100644
--- a/test/nag.bats
+++ b/test/nag.bats
@@ -71,6 +71,11 @@ load test_helper
   [ "${status}" -eq 1 ]
 }
 
+@test "at with explicit past date fails" {
+  run_nag at "yesterday 3pm" "too late"
+  [ "${status}" -eq 1 ]
+}
+
 @test "at without message fails" {
   run_nag at "tomorrow 3pm"
   [ "${status}" -eq 1 ]