diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4f981c4a..d8437c16a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+**Features**:
+
+- Change the timestamp resolution to microseconds. ([#995](https://github.com/getsentry/sentry-native/pull/995))
+
 ## 0.7.4
 
 **Fixes**:
diff --git a/src/backends/sentry_backend_crashpad.cpp b/src/backends/sentry_backend_crashpad.cpp
index ad7d5846a..19df8bf81 100644
--- a/src/backends/sentry_backend_crashpad.cpp
+++ b/src/backends/sentry_backend_crashpad.cpp
@@ -554,7 +554,7 @@ report_crash_time(
     // can have a session that starts at, e.g. `0.471`, whereas the crashpad
     // report will be `0`, which would mean our heuristic does not trigger due
     // to rounding.
-    uint64_t time = ((uint64_t)report.creation_time + 1) * 1000;
+    uint64_t time = (static_cast<uint64_t>(report.creation_time) + 1) * 1000000;
     if (time > *crash_time) {
         *crash_time = time;
     }
diff --git a/src/sentry_core.c b/src/sentry_core.c
index c9ef8cd45..55241aa75 100644
--- a/src/sentry_core.c
+++ b/src/sentry_core.c
@@ -869,7 +869,7 @@ sentry_transaction_start(
 
     sentry_value_set_by_key(tx, "start_timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
 
     sentry__transaction_context_free(opaque_tx_cxt);
     return sentry__transaction_new(tx);
@@ -914,7 +914,7 @@ sentry_transaction_finish(sentry_transaction_t *opaque_tx)
     sentry_value_set_by_key(tx, "type", sentry_value_new_string("transaction"));
     sentry_value_set_by_key(tx, "timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
     // TODO: This might not actually be necessary. Revisit after talking to
     // the relay team about this.
     sentry_value_set_by_key(tx, "level", sentry_value_new_string("info"));
@@ -1111,7 +1111,7 @@ sentry_span_finish(sentry_span_t *opaque_span)
 
     sentry_value_set_by_key(span, "timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
     sentry_value_remove_by_key(span, "sampled");
 
     size_t max_spans = SENTRY_SPANS_MAX;
diff --git a/src/sentry_database.c b/src/sentry_database.c
index d9874fcdb..6ebe89008 100644
--- a/src/sentry_database.c
+++ b/src/sentry_database.c
@@ -203,10 +203,10 @@ sentry__process_old_runs(const sentry_options_t *options, uint64_t last_crash)
                     // time.
                     if (session->status == SENTRY_SESSION_STATUS_OK) {
                         bool was_crash
-                            = last_crash && last_crash > session->started_ms;
+                            = last_crash && last_crash > session->started_us;
                         if (was_crash) {
-                            session->duration_ms
-                                = last_crash - session->started_ms;
+                            session->duration_us
+                                = last_crash - session->started_us;
                             session->errors += 1;
                             // we only set at most one unclosed session as
                             // crashed
@@ -248,7 +248,7 @@ static const char *g_last_crash_filename = "last_crash";
 bool
 sentry__write_crash_marker(const sentry_options_t *options)
 {
-    char *iso_time = sentry__msec_time_to_iso8601(sentry__msec_time());
+    char *iso_time = sentry__usec_time_to_iso8601(sentry__usec_time());
     if (!iso_time) {
         return false;
     }
diff --git a/src/sentry_envelope.c b/src/sentry_envelope.c
index b71242c1d..615197654 100644
--- a/src/sentry_envelope.c
+++ b/src/sentry_envelope.c
@@ -288,7 +288,7 @@ sentry__envelope_add_transaction(
     sentry_value_t now = sentry_value_new_string("2021-12-16T05:53:59.343Z");
 #else
     sentry_value_t now = sentry__value_new_string_owned(
-        sentry__msec_time_to_iso8601(sentry__msec_time()));
+        sentry__usec_time_to_iso8601(sentry__usec_time()));
 #endif
     sentry__envelope_set_header(envelope, "sent_at", now);
 
diff --git a/src/sentry_json.c b/src/sentry_json.c
index f83cd1886..904ee4825 100644
--- a/src/sentry_json.c
+++ b/src/sentry_json.c
@@ -278,9 +278,9 @@ sentry__jsonwriter_write_uuid(
 }
 
 void
-sentry__jsonwriter_write_msec_timestamp(sentry_jsonwriter_t *jw, uint64_t time)
+sentry__jsonwriter_write_usec_timestamp(sentry_jsonwriter_t *jw, uint64_t time)
 {
-    char *formatted = sentry__msec_time_to_iso8601(time);
+    char *formatted = sentry__usec_time_to_iso8601(time);
     sentry__jsonwriter_write_str(jw, formatted);
     sentry_free(formatted);
 }
diff --git a/src/sentry_json.h b/src/sentry_json.h
index 1ff9a11c7..8379bf021 100644
--- a/src/sentry_json.h
+++ b/src/sentry_json.h
@@ -58,11 +58,11 @@ void sentry__jsonwriter_write_uuid(
     sentry_jsonwriter_t *jw, const sentry_uuid_t *uuid);
 
 /**
- * This will write a millisecond resolution timestamp formattad as an ISO8601
+ * This will write a microsecond resolution timestamp formattad as an ISO8601
  * string.
- * See `sentry__msec_time_to_iso8601`.
+ * See `sentry__usec_time_to_iso8601`.
  */
-void sentry__jsonwriter_write_msec_timestamp(
+void sentry__jsonwriter_write_usec_timestamp(
     sentry_jsonwriter_t *jw, uint64_t time);
 
 /**
diff --git a/src/sentry_session.c b/src/sentry_session.c
index e782d385f..6c8589497 100644
--- a/src/sentry_session.c
+++ b/src/sentry_session.c
@@ -76,8 +76,8 @@ sentry__session_new(void)
     rv->status = SENTRY_SESSION_STATUS_OK;
     rv->init = true;
     rv->errors = 0;
-    rv->started_ms = sentry__msec_time();
-    rv->duration_ms = (uint64_t)-1;
+    rv->started_us = sentry__usec_time();
+    rv->duration_us = (uint64_t)-1;
 
     return rv;
 }
@@ -119,17 +119,18 @@ sentry__session_to_json(
     sentry__jsonwriter_write_int32(jw, (int32_t)session->errors);
 
     sentry__jsonwriter_write_key(jw, "started");
-    sentry__jsonwriter_write_msec_timestamp(jw, session->started_ms);
+    sentry__jsonwriter_write_usec_timestamp(jw, session->started_us);
 
     // if there is a duration stored on the struct (that happens after
     // reading back from disk) we use that, otherwise we calculate the
     // difference to the start time.
     sentry__jsonwriter_write_key(jw, "duration");
     double duration;
-    if (session->duration_ms != (uint64_t)-1) {
-        duration = (double)session->duration_ms / 1000.0;
+    if (session->duration_us != (uint64_t)-1) {
+        duration = (double)session->duration_us / 1000000.0;
     } else {
-        duration = (double)(sentry__msec_time() - session->started_ms) / 1000.0;
+        duration
+            = (double)(sentry__usec_time() - session->started_us) / 1000000.0;
     }
     sentry__jsonwriter_write_double(jw, duration);
 
@@ -184,12 +185,12 @@ sentry__session_from_json(const char *buf, size_t buflen)
 
     rv->errors = (int64_t)sentry_value_as_int32(
         sentry_value_get_by_key(value, "errors"));
-    rv->started_ms = sentry__iso8601_to_msec(
+    rv->started_us = sentry__iso8601_to_usec(
         sentry_value_as_string(sentry_value_get_by_key(value, "started")));
 
     double duration
         = sentry_value_as_double(sentry_value_get_by_key(value, "duration"));
-    rv->duration_ms = (uint64_t)(duration * 1000);
+    rv->duration_us = (uint64_t)(duration * 1000000);
 
     sentry_value_decref(value);
 
diff --git a/src/sentry_session.h b/src/sentry_session.h
index 2a18edb4c..d95cc6871 100644
--- a/src/sentry_session.h
+++ b/src/sentry_session.h
@@ -17,8 +17,8 @@ typedef struct sentry_session_s {
     char *environment;
     sentry_uuid_t session_id;
     sentry_value_t distinct_id;
-    uint64_t started_ms;
-    uint64_t duration_ms;
+    uint64_t started_us;
+    uint64_t duration_us;
     uint64_t errors;
     sentry_session_status_t status;
     long init;
diff --git a/src/sentry_tracing.c b/src/sentry_tracing.c
index bbc7f00b4..5f3ae7c69 100644
--- a/src/sentry_tracing.c
+++ b/src/sentry_tracing.c
@@ -327,7 +327,7 @@ sentry__value_span_new_n(size_t max_spans, sentry_value_t parent,
         sentry_value_new_string_n(description.ptr, description.len));
     sentry_value_set_by_key(child, "start_timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
 
     return child;
 fail:
diff --git a/src/sentry_utils.c b/src/sentry_utils.c
index 45f32081e..f2980b728 100644
--- a/src/sentry_utils.c
+++ b/src/sentry_utils.c
@@ -374,11 +374,11 @@ sentry__dsn_get_minidump_url(const sentry_dsn_t *dsn, const char *user_agent)
 }
 
 char *
-sentry__msec_time_to_iso8601(uint64_t time)
+sentry__usec_time_to_iso8601(uint64_t time)
 {
     char buf[64];
     size_t buf_len = sizeof(buf);
-    time_t secs = time / 1000;
+    time_t secs = time / 1000000;
     struct tm *tm;
 #ifdef SENTRY_PLATFORM_WINDOWS
     tm = gmtime(&secs);
@@ -397,10 +397,10 @@ sentry__msec_time_to_iso8601(uint64_t time)
         return NULL;
     }
 
-    int msecs = time % 1000;
-    if (msecs) {
+    int usecs = time % 1000000;
+    if (usecs) {
         size_t rv = (size_t)snprintf(
-            buf + written, buf_len - written, ".%03d", msecs);
+            buf + written, buf_len - written, ".%06d", usecs);
         if (rv >= buf_len - written) {
             return NULL;
         }
@@ -416,14 +416,14 @@ sentry__msec_time_to_iso8601(uint64_t time)
 }
 
 uint64_t
-sentry__iso8601_to_msec(const char *iso)
+sentry__iso8601_to_usec(const char *iso)
 {
     size_t len = strlen(iso);
-    if (len != 20 && len != 24) {
+    if (len != 20 && len != 27) {
         return 0;
     }
     // The code is adapted from: https://stackoverflow.com/a/26896792
-    int y, M, d, h, m, s, msec = 0;
+    int y, M, d, h, m, s, usec = 0;
     int consumed = 0;
     if (sscanf(iso, "%d-%d-%dT%d:%d:%d%n", &y, &M, &d, &h, &m, &s, &consumed)
             < 6
@@ -431,9 +431,10 @@ sentry__iso8601_to_msec(const char *iso)
         return 0;
     }
     iso += consumed;
-    // we optionally have millisecond precision
+    // we optionally have microsecond precision
     if (iso[0] == '.') {
-        if (sscanf(iso, ".%d%n", &msec, &consumed) < 1 || consumed != 4) {
+        if (sscanf(iso, ".%d%n", &usec, &consumed) < 1 || consumed != 7) {
+            printf("consumed = %d\n", consumed);
             return 0;
         }
         iso += consumed;
@@ -482,7 +483,7 @@ sentry__iso8601_to_msec(const char *iso)
         return 0;
     }
 
-    return (uint64_t)time * 1000 + msec;
+    return (uint64_t)time * 1000000 + usec;
 }
 
 #ifdef SENTRY_PLATFORM_WINDOWS
diff --git a/src/sentry_utils.h b/src/sentry_utils.h
index b5b8e9d3e..41678d7d4 100644
--- a/src/sentry_utils.h
+++ b/src/sentry_utils.h
@@ -97,10 +97,10 @@ char *sentry__dsn_get_minidump_url(
     const sentry_dsn_t *dsn, const char *user_agent);
 
 /**
- * Returns the number of milliseconds since the unix epoch.
+ * Returns the number of microseconds since the unix epoch.
  */
 static inline uint64_t
-sentry__msec_time(void)
+sentry__usec_time(void)
 {
 #ifdef SENTRY_PLATFORM_WINDOWS
     // Contains a 64-bit value representing the number of 100-nanosecond
@@ -113,13 +113,13 @@ sentry__msec_time(void)
     uint64_t timestamp = (uint64_t)file_time.dwLowDateTime
         + ((uint64_t)file_time.dwHighDateTime << 32);
     timestamp -= 116444736000000000LL; // convert to unix epoch
-    timestamp /= 10000LL; // 100ns -> 1ms
+    timestamp /= 10LL; // 100ns -> 1us
 
     return timestamp;
 #else
     struct timeval tv;
     return (gettimeofday(&tv, NULL) == 0)
-        ? (uint64_t)tv.tv_sec * 1000 + tv.tv_usec / 1000
+        ? (uint64_t)tv.tv_sec * 1000000 + tv.tv_usec
         : 0;
 #endif
 }
@@ -180,16 +180,16 @@ sentry__monotonic_time(void)
 }
 
 /**
- * Formats a timestamp (milliseconds since epoch) into ISO8601 format.
+ * Formats a timestamp (microseconds since epoch) into ISO8601 format.
  */
-char *sentry__msec_time_to_iso8601(uint64_t time);
+char *sentry__usec_time_to_iso8601(uint64_t time);
 
 /**
- * Parses a ISO8601 formatted string into a millisecond resolution timestamp.
- * This only accepts the format `YYYY-MM-DD'T'hh:mm:ss(.zzz)'Z'`, which is
- * produced by the `sentry__msec_time_to_iso8601` function.
+ * Parses a ISO8601 formatted string into a microsecond resolution timestamp.
+ * This only accepts the format `YYYY-MM-DD'T'hh:mm:ss(.zzzzzz)'Z'`, which is
+ * produced by the `sentry__usec_time_to_iso8601` function.
  */
-uint64_t sentry__iso8601_to_msec(const char *iso);
+uint64_t sentry__iso8601_to_usec(const char *iso);
 
 /**
  * Locale independent (or rather, using "C" locale) `strtod`.
diff --git a/src/sentry_value.c b/src/sentry_value.c
index 3c3e344c9..e2315914b 100644
--- a/src/sentry_value.c
+++ b/src/sentry_value.c
@@ -1121,7 +1121,7 @@ sentry_value_new_event(void)
 
     sentry_value_set_by_key(rv, "timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
 
     sentry_value_set_by_key(rv, "platform", sentry_value_new_string("native"));
 
@@ -1162,7 +1162,7 @@ timestamp_value(sentry_value_t value)
 {
     sentry_value_set_by_key(value, "timestamp",
         sentry__value_new_string_owned(
-            sentry__msec_time_to_iso8601(sentry__msec_time())));
+            sentry__usec_time_to_iso8601(sentry__usec_time())));
 }
 
 sentry_value_t
diff --git a/tests/unit/test_utils.c b/tests/unit/test_utils.c
index 232303415..9fb5421f7 100644
--- a/tests/unit/test_utils.c
+++ b/tests/unit/test_utils.c
@@ -9,22 +9,22 @@
 
 SENTRY_TEST(iso_time)
 {
-    uint64_t msec;
+    uint64_t usec;
     char *str;
 
-    msec = sentry__iso8601_to_msec("1970-01-01T00:00:10Z");
-    TEST_CHECK_INT_EQUAL(msec, 10 * 1000);
-    msec = sentry__iso8601_to_msec("2020-04-27T11:02:36.050Z");
-    TEST_CHECK_INT_EQUAL(msec, 1587985356050);
-    str = sentry__msec_time_to_iso8601(msec);
-    TEST_CHECK_STRING_EQUAL(str, "2020-04-27T11:02:36.050Z");
+    usec = sentry__iso8601_to_usec("1970-01-01T00:00:10Z");
+    TEST_CHECK_INT_EQUAL(usec, 10 * 1000000);
+    usec = sentry__iso8601_to_usec("2020-04-27T11:02:36.050505Z");
+    TEST_CHECK_INT_EQUAL(usec, 1587985356050505);
+    str = sentry__usec_time_to_iso8601(usec);
+    TEST_CHECK_STRING_EQUAL(str, "2020-04-27T11:02:36.050505Z");
     sentry_free(str);
 
-    msec = sentry__msec_time();
-    str = sentry__msec_time_to_iso8601(msec);
-    uint64_t roundtrip = sentry__iso8601_to_msec(str);
+    usec = sentry__usec_time();
+    str = sentry__usec_time_to_iso8601(usec);
+    uint64_t roundtrip = sentry__iso8601_to_usec(str);
     sentry_free(str);
-    TEST_CHECK_INT_EQUAL(roundtrip, msec);
+    TEST_CHECK_INT_EQUAL(roundtrip, usec);
 }
 
 SENTRY_TEST(url_parsing_complete)