diff --git a/gtk2_ardour/editor_rulers.cc b/gtk2_ardour/editor_rulers.cc
index c53f2bf3db..a0e9255741 100644
--- a/gtk2_ardour/editor_rulers.cc
+++ b/gtk2_ardour/editor_rulers.cc
@@ -45,6 +45,8 @@
 #include "ardour/tempo.h"
 #include "ardour/profile.h"
 
+#include "temporal/tempo.h"
+
 #include "gtkmm2ext/gtk_ui.h"
 #include "gtkmm2ext/keyboard.h"
 
@@ -989,8 +991,8 @@ Editor::compute_bbt_ruler_scale (samplepos_t lower, samplepos_t upper)
 	const samplepos_t beat_before_lower_pos = tmap->sample_at (floor_lower_beat);
 	const samplepos_t beat_after_upper_pos = tmap->sample_at ((std::max (Beats(), tmap->quarters_at_sample  (upper)).round_down_to_beat()) + Beats (1, 0));
 
-	_session->bbt_time (timepos_t (beat_before_lower_pos), lower_beat);
-	_session->bbt_time (timepos_t (beat_after_upper_pos), upper_beat);
+	lower_beat = Temporal::TempoMap::use()->bbt_at (timepos_t (beat_before_lower_pos));
+	upper_beat = Temporal::TempoMap::use()->bbt_at (timepos_t (beat_after_upper_pos));
 	uint32_t beats = 0;
 
 	bbt_bar_helper_on = false;
diff --git a/gtk2_ardour/export_format_dialog.cc b/gtk2_ardour/export_format_dialog.cc
index af03123dad..ec765b80b1 100644
--- a/gtk2_ardour/export_format_dialog.cc
+++ b/gtk2_ardour/export_format_dialog.cc
@@ -27,6 +27,8 @@
 #include "ardour/export_format_specification.h"
 #include "ardour/session.h"
 
+#include "temporal/tempo.h"
+
 #include "widgets/tooltips.h"
 
 #include "export_format_dialog.h"
@@ -1032,7 +1034,7 @@ ExportFormatDialog::update_time (AnyTime& time, AudioClock const& clock)
 		break;
 	case AudioClock::BBT:
 		time.type = AnyTime::BBT;
-		_session->bbt_time (timepos_t (samples), time.bbt);
+		time.bbt = Temporal::TempoMap::use()->bbt_at (timepos_t (samples));
 		break;
 	case AudioClock::Seconds:
 	case AudioClock::MinSec:
diff --git a/gtk2_ardour/export_timespan_selector.cc b/gtk2_ardour/export_timespan_selector.cc
index 444b8aab0f..cc1a92de2e 100644
--- a/gtk2_ardour/export_timespan_selector.cc
+++ b/gtk2_ardour/export_timespan_selector.cc
@@ -34,6 +34,8 @@
 #include "ardour/export_handler.h"
 #include "ardour/export_timespan.h"
 
+#include "temporal/tempo.h"
+
 #include "export_timespan_selector.h"
 
 #include "pbd/i18n.h"
@@ -302,7 +304,7 @@ ExportTimespanSelector::bbt_str (samplepos_t samples) const
 
 	std::ostringstream oss;
 	Temporal::BBT_Time time;
-	_session->bbt_time (timepos_t (samples), time);
+	time = Temporal::TempoMap::use()->bbt_at (timepos_t (samples));
 
 	time.print_padded (oss);
 
diff --git a/gtk2_ardour/verbose_cursor.cc b/gtk2_ardour/verbose_cursor.cc
index d8a22b682c..c8e1dcd97b 100644
--- a/gtk2_ardour/verbose_cursor.cc
+++ b/gtk2_ardour/verbose_cursor.cc
@@ -113,7 +113,7 @@ VerboseCursor::set_time (samplepos_t sample)
 
 	switch (m) {
 	case AudioClock::BBT:
-		_editor->_session->bbt_time (timepos_t (sample), bbt);
+		bbt = TempoMap::use()->bbt_at (timepos_t (sample));
 		snprintf (buf, sizeof (buf), "%02" PRIu32 "|%02" PRIu32 "|%02" PRIu32, bbt.bars, bbt.beats, bbt.ticks);
 		break;
 
@@ -156,8 +156,8 @@ VerboseCursor::set_duration (samplepos_t start, samplepos_t end)
 	switch (m) {
 	case AudioClock::BBT:
 	{
-		_editor->_session->bbt_time (timepos_t (start), sbbt);
-		_editor->_session->bbt_time (timepos_t (end), ebbt);
+		sbbt = TempoMap::use()->bbt_at (timepos_t (start));
+		ebbt = TempoMap::use()->bbt_at (timepos_t (end));
 
 		/* subtract */
 		/* XXX this computation won't work well if the