Automatically fix invalid timestamps, instead of crashing

android/uhabits-core/src/main/java/org/isoron/uhabits/core/models/Timestamp.java

@@ -30,7 +30,6 @@ import static org.isoron.uhabits.core.utils.StringUtils.*;
 
 public final class Timestamp
 {
-
     public static final long DAY_LENGTH = 86400000;
 
     public static final Timestamp ZERO = new Timestamp(0);
@@ -39,10 +38,13 @@ public final class Timestamp
 
     public Timestamp(long unixTime)
     {
-        if (unixTime < 0 || unixTime % DAY_LENGTH != 0)
+        if (unixTime < 0)
             throw new IllegalArgumentException(
                 "Invalid unix time: " + unixTime);
 
+        if (unixTime % DAY_LENGTH != 0)
+            unixTime = (unixTime / DAY_LENGTH) * DAY_LENGTH;
+
         this.unixTime = unixTime;
     }
 

android/uhabits-core/src/test/java/org/isoron/uhabits/core/models/TimestampTest.java

@@ -22,6 +22,7 @@ package org.isoron.uhabits.core.models;
 import org.isoron.uhabits.core.*;
 import org.isoron.uhabits.core.utils.*;
 import org.junit.*;
+import org.mockito.internal.verification.*;
 
 import static junit.framework.TestCase.assertFalse;
 import static org.hamcrest.MatcherAssert.*;
@@ -64,5 +65,10 @@ public class TimestampTest extends BaseUnitTest
         assertThat(t.daysUntil(t.minus(300)), equalTo(-300));
     }
 
-
+    @Test
+    public void testInexact() throws Exception
+    {
+        Timestamp t = new Timestamp(1578054764000L);
+        assertThat(t.getUnixTime(), equalTo(1578009600000L));
+    }
 }