diff --git a/app/models/card/entropic.rb b/app/models/card/entropic.rb
index 23e33c18a..b238156f9 100644
--- a/app/models/card/entropic.rb
+++ b/app/models/card/entropic.rb
@@ -7,7 +7,7 @@ module Card::Entropic
         .joins(board: :account)
         .left_outer_joins(board: :entropy)
         .joins("LEFT OUTER JOIN entropies AS account_entropies ON account_entropies.account_id = accounts.id AND account_entropies.container_type = 'Account' AND account_entropies.container_id = accounts.id")
-        .where("last_active_at <= DATE_SUB(?, INTERVAL COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period) SECOND)", Time.now)
+        .where("last_active_at <= #{connection.date_subtract('?', 'COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period)')}", Time.now)
     end
 
     scope :postponing_soon, -> do
@@ -16,8 +16,8 @@ module Card::Entropic
         .joins(board: :account)
         .left_outer_joins(board: :entropy)
         .joins("LEFT OUTER JOIN entropies AS account_entropies ON account_entropies.account_id = accounts.id AND account_entropies.container_type = 'Account' AND account_entropies.container_id = accounts.id")
-        .where("last_active_at >  DATE_SUB(?, INTERVAL COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period) SECOND)", now)
-        .where("last_active_at <= DATE_SUB(?, INTERVAL CAST(COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period) * 0.75 AS SIGNED) SECOND)", now)
+        .where("last_active_at > #{connection.date_subtract('?', 'COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period)')}", now)
+        .where("last_active_at <= #{connection.date_subtract('?', 'COALESCE(entropies.auto_postpone_period, account_entropies.auto_postpone_period) * 0.75')}", now)
     end
 
     delegate :auto_postpone_period, to: :board
diff --git a/lib/rails_ext/active_record_date_arithmetic.rb b/lib/rails_ext/active_record_date_arithmetic.rb
new file mode 100644
index 000000000..5121c3f12
--- /dev/null
+++ b/lib/rails_ext/active_record_date_arithmetic.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+# Adds database-agnostic date arithmetic methods to ActiveRecord adapters.
+# This allows code to perform date calculations without checking which database adapter is in use.
+#
+# Usage:
+#   connection.date_subtract("created_at", "3600")
+#   # MySQL/Trilogy: "DATE_SUB(created_at, INTERVAL 3600 SECOND)"
+#   # SQLite: "datetime(created_at, '-' || (3600) || ' seconds')"
+
+# Module for MySQL-based adapters (Trilogy, Mysql2, etc.)
+module MysqlDateArithmetic
+  # Generates SQL for subtracting seconds from a date/time column in MySQL.
+  #
+  # @param date_column [String] The date/time column or expression
+  # @param seconds_expression [String] SQL expression that evaluates to number of seconds
+  # @return [String] MySQL DATE_SUB expression
+  #
+  # Example:
+  #   date_subtract("last_active_at", "COALESCE(auto_postpone_period, 3600)")
+  #   # => "DATE_SUB(last_active_at, INTERVAL COALESCE(auto_postpone_period, 3600) SECOND)"
+  def date_subtract(date_column, seconds_expression)
+    "DATE_SUB(#{date_column}, INTERVAL #{seconds_expression} SECOND)"
+  end
+end
+
+# Module for SQLite adapter
+module SqliteDateArithmetic
+  # Generates SQL for subtracting seconds from a date/time column in SQLite.
+  #
+  # @param date_column [String] The date/time column or expression
+  # @param seconds_expression [String] SQL expression that evaluates to number of seconds
+  # @return [String] SQLite datetime expression
+  #
+  # Example:
+  #   date_subtract("last_active_at", "COALESCE(auto_postpone_period, 3600)")
+  #   # => "datetime(last_active_at, '-' || (COALESCE(auto_postpone_period, 3600)) || ' seconds')"
+  def date_subtract(date_column, seconds_expression)
+    "datetime(#{date_column}, '-' || (#{seconds_expression}) || ' seconds')"
+  end
+end
+
+ActiveSupport.on_load(:active_record) do
+  # Prepend MySQL date arithmetic to AbstractMysqlAdapter (covers Trilogy, Mysql2, etc.)
+  if defined?(ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter)
+    ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter.prepend(MysqlDateArithmetic)
+  end
+
+  # Prepend SQLite date arithmetic to SQLite3Adapter
+  if defined?(ActiveRecord::ConnectionAdapters::SQLite3Adapter)
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.prepend(SqliteDateArithmetic)
+  end
+end